Method and apparatus for aligning antenna beams in high-low frequency co-site network

ABSTRACT

A method and an apparatus for aligning antenna beams in a high-low frequency co-site network, where the method includes performing antenna alignment of a low frequency beam with a communications device in order to establish a low frequency channel, and performing high frequency beam alignment of a high frequency antenna with the communications device using the low frequency channel. In the method, high frequency beam alignment of a high frequency antenna is performed using an established low frequency channel. Therefore, a technical problem that a high frequency beam alignment time of a high frequency antenna is long due to a narrow field of view of a high frequency beam can be avoided in order to quickly implement high frequency beam alignment of a high frequency antenna.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of International Patent ApplicationNo. PCT/CN2014/095302 filed on Dec. 29, 2014, which is herebyincorporated by reference in its entirety.

TECHNICAL FIELD

Embodiments of the present disclosure relate to the communicationsfield, and in particular, to a method and an apparatus for aligningantenna beams in a high-low frequency co-site network.

BACKGROUND

In a communications system that includes a macro base station (MacroBS), a small cell (Micro Base Station (Micro BS))/Pico Base Station(Pico BS), and user equipment (UE), the small cell is a base stationaccessed by UE, and directly serves UE such as a mobile phone, and theMacro BS may connect to a core network using a wired or microwavecommunication link or the like. A problem in the communications systemis how to transmit service data of a terminal user to the Macro BS.

Currently, the foregoing problem is usually resolved using the followingtwo solutions. One solution is to use a wired connection such as a cableor a fiber, but both wiring costs and manpower costs of this solutionare extremely high. The other solution is to use a wireless backhaultechnology. The wireless backhaul technology may be a microwave, or maybe a low-carrier wireless technology based on WI-FI, the 802.16protocol, or Long Term Evolution (LTE). In order to reduce power andnetwork interference, the wireless backhaul technology generally uses adirectional antenna.

The directional antenna is used in the wireless backhaul technology.Therefore, if a signal transmission direction is not aligned with adestination antenna, that is, a maximum gain point of a transmit antennaand a maximum gain point of a destination antenna are not aligned,signal quality is deteriorated, or power is wasted severely. Therefore,how to implement antenna alignment becomes an important problem thatneeds to be resolved in the wireless backhaul solution.

Compared with a high frequency signal, a low frequency signal has alower data transmission rate, a wider field of view of a low frequencybeam, a lower frequency, and lower power consumption of datatransmission and exchange. Compared with a low frequency signal, a highfrequency signal has a higher data transmission rate, a narrower fieldof view of a high frequency beam, a higher frequency, and higher powerconsumption of data transmission and exchange.

When a frequency of a radio frequency (RF) antenna is relatively low, afield of view of a low frequency antenna beam is relatively wide, andbeam alignment does not need to be performed when a low frequencyantenna is accessed. When the frequency of the RF antenna is relativelyhigh, a field of view of a high frequency antenna beam is relativelynarrow, and high frequency beam alignment of a high frequency antennaneeds to be performed when a high frequency antenna is accessed.However, because a field of view of a high frequency beam is narrow,high frequency beam alignment is relatively difficult, and costs arelatively long time.

SUMMARY

Embodiments of the present disclosure provide a method and an apparatusfor aligning antenna beams in a high-low frequency co-site network inorder to quickly implement high frequency beam alignment of a highfrequency antenna.

A first aspect provides a method for aligning antenna beams in ahigh-low frequency co-site network, including establishing a lowfrequency channel with a low frequency antenna of a communicationsdevice, obtaining location information of the communications deviceusing the low frequency channel, determining a scanning range of thehigh frequency beam according to the location information of thecommunications device, and performing high frequency beam alignment of ahigh frequency antenna with the communications device according to thescanning range of the high frequency beam.

A second aspect provides a method for aligning an antenna in a high-lowfrequency co-site network, including establishing a low frequencychannel with a low frequency antenna of a communications device,obtaining location information of the communications device using thelow frequency channel, determining a scanning range of the highfrequency beam according to the location information of thecommunications device, and performing high frequency beam alignment of ahigh frequency antenna with the communications device according to thescanning range of the high frequency beam.

A third aspect provides an apparatus for aligning antenna beams in ahigh-low frequency co-site network, including an establishment unitconfigured to establish a low frequency channel with a low frequencyantenna of a communications device, an obtaining unit configured toobtain location information of the communications device using the lowfrequency channel established by the establishment unit, a determiningunit configured to determine a scanning range of the high frequency beamaccording to the location information of the communications device thatis obtained by the obtaining unit, and an alignment unit configured toperform high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range that is of thehigh frequency beam and is determined by the determining unit.

A fourth aspect provides an apparatus for aligning an antenna in ahigh-low frequency co-site network, including an establishment unitconfigured to establish a low frequency channel with a low frequencyantenna of a communications device, an obtaining unit configured toobtain location information of the communications device using the lowfrequency channel established by the establishment unit, a determiningunit configured to determine a scanning range of the high frequency beamaccording to the location information of the communications device thatis obtained by the obtaining unit, and an alignment unit configured toperform high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range that is of thehigh frequency beam and is determined by the determining unit.

In the embodiments of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time is long due to a narrow field of view of ahigh frequency beam can be avoided such that high frequency beamalignment of a high frequency antenna can be quickly implemented.

BRIEF DESCRIPTION OF DRAWINGS

In order to describe the technical solutions in the embodiments of thepresent disclosure more clearly, the following briefly describes theaccompanying drawings required for describing the embodiments of thepresent disclosure. The accompanying drawings in the followingdescription show merely some embodiments of the present disclosure, anda person of ordinary skill in the art may still derive other drawingsfrom these accompanying drawings without creative efforts.

FIG. 1 is a schematic diagram of an example of a system scenario towhich embodiments of the present disclosure may be applied;

FIG. 2 is a schematic flowchart of a method for aligning antenna beamsin a high-low frequency co-site network according to an embodiment ofthe present disclosure;

FIG. 3 is a schematic flowchart of a method for aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure;

FIG. 4 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to an embodiment ofthe present disclosure;

FIG. 5 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure;

FIG. 6 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure;

FIG. 7 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure;

FIG. 8 is a signaling flowchart of aligning antenna beams in a high-lowfrequency co-site network according to an embodiment of the presentdisclosure;

FIG. 9 is a signaling flowchart of aligning antenna beams in a high-lowfrequency co-site network according to another embodiment of the presentdisclosure;

FIG. 10 is a block diagram of a base station for aligning antenna beamsin a high-low frequency co-site network according to an embodiment ofthe present disclosure;

FIG. 11 is a block diagram of a mobile terminal for aligning antennabeams in a high-low frequency co-site network according to anotherembodiment of the present disclosure;

FIG. 12 is a block diagram of a base station for aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure; and

FIG. 13 is a block diagram of a mobile terminal for aligning antennabeams in a high-low frequency co-site network according to anotherembodiment of the present disclosure.

DESCRIPTION OF EMBODIMENTS

The following clearly describes the technical solutions in theembodiments of the present disclosure with reference to the accompanyingdrawings in the embodiments of the present disclosure. The describedembodiments are some rather than all of the embodiments of the presentdisclosure. All other embodiments obtained by a person of ordinary skillin the art based on the embodiments of the present disclosure withoutcreative efforts shall fall within the protection scope of the presentdisclosure.

It should be understood that the technical solutions of the embodimentsof the present disclosure may be applied to various communicationssystems, for example, a Global System for Mobile Communications (GSM), aCode Division Multiple Access (CDMA) system, a Wideband Code DivisionMultiple Access (WCDMA) system, a general packet radio service (GPRS),an LTE system, an LTE frequency division duplex (FDD) system, LTE timedivision duplex (TDD), a Universal Mobile Telecommunications System(UMTS), or a Worldwide Interoperability for Microwave Access (WIMAX)communications system.

A base station may be a base transceiver station (BTS) in GSM or CDMA,may be a NodeB (NB) in WCDMA, or may be an evolved NodeB (eNB ore-NodeB) in LTE. This is not limited in the present disclosure.

UE may be referred to as a terminal, a mobile station (MS), a mobileterminal, or the like. The UE may communicate with one or more corenetworks using a radio access network (RAN). For example, the UE may bea mobile phone (or referred to as a “cellular” phone), a computer havinga mobile terminal, or the like. Alternatively, the UE may be a portable,pocket-sized, handheld, computer built-in, or in-vehicle mobileapparatus that exchanges voice and/or data with the RAN.

FIG. 1 is a schematic diagram of an example of a system scenario towhich embodiments of the present disclosure may be applied.

As shown in FIG. 1, a high-low frequency co-site network system 100includes a first communications device and a second communicationsdevice. The first communications device may be a base station 101 shownin FIG. 1, or may be an access device such as a hotspot or an accesspoint. The second communications device may be a small cell 102 shown inFIG. 1, or may be a mobile terminal 103 shown in FIG. 1. In the high-lowfrequency co-site network system 100, the first communications deviceincludes a high frequency antenna and a low frequency antenna, and thesecond communications device also includes a high frequency antenna anda low frequency antenna. A low frequency antenna has a relatively largecoverage area, and a high frequency antenna has a relatively smallcoverage area. For example, a coverage area of a low frequency antennaof the base station 101 is shown by 104 in FIG. 1, and a coverage areaof a high frequency antenna of the base station 101 is shown by 105 inFIG. 1.

In a single-frequency frequency network system, a base station 101 makesno rough estimation of a location of a mobile terminal 103 such thatscanning ranges of a base station antenna and a mobile terminal antennabecome wide. In addition, the base station 101 and the mobile terminal103 gave no temporally synchronous handshake to each other, and arecompletely in a blind scanning state. Consequently, beam alignment costsa long time. Particularly, in a network system having only a highfrequency antenna, a coverage area of the high frequency antenna isrelatively small, and a field of view of a high frequency beam isrelatively narrow. Consequently, high frequency beam alignment of a highfrequency antenna is more difficult, and may need a longer time.

For the high-low frequency co-site network system 100 in FIG. 1, forexample, the first communications device includes the base station 101,and the second communications device includes the mobile terminal 103.When cell search is synchronized, both low frequency linksynchronization between the base station 101 and the mobile terminal 103and high frequency beam alignment of high frequency antennas of the basestation 101 and the mobile terminal 103 need to be performed in order toimplement high frequency link synchronization. The base station 101 andthe mobile terminal 103 may first perform low frequency linksynchronization to establish a low frequency channel, and then exchangehigh frequency beam alignment information of a high frequency antennausing the successfully established low frequency channel. In this way,high frequency link synchronization can be quickly implemented such thatan antenna beam alignment time can be shortened.

FIG. 2 is a schematic flowchart of a method for aligning antenna beamsin a high-low frequency co-site network according to an embodiment ofthe present disclosure. The method in FIG. 2 may be executed by thefirst communications device (for example, the base station 101) in FIG.1.

Step 201: Establish a low frequency channel with a low frequency antennaof a communications device.

Step 202: Obtain location information of the communications device usingthe low frequency channel.

Step 203: Determine a scanning range of a high frequency beam accordingto the location information of the communications device.

Step 204: Perform high frequency beam alignment of a high frequencyantenna with the communications device according to the scanning rangeof the high frequency beam.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time of a high frequency antenna is long due toa narrow field of view of a high frequency beam can be avoided such thathigh frequency beam alignment of a high frequency antenna can be quicklyimplemented.

This embodiment of the present disclosure provides description using anexample in which a first communications device is a base station, suchas the base station 101 shown in FIG. 1, and a second communicationsdevice is a mobile terminal, such as the mobile terminal 103 shown inFIG. 1. However, the present disclosure is not limited thereto.

In step 201, the mobile terminal scans a low frequency beam of the basestation using a low-frequency wide beam to search for a target cell, andthen completes procedures such as symbol-level timing detection, radioframe clock detection, and cell identity (ID) detection on the lowfrequency channel to implement low frequency link synchronization.

It should be understood that a low-frequency wide beam sent by the basestation may be divided into multiple sectors using an existing beamforming technology, and each sector covers an angle. Alternatively, alow-frequency wide beam sent by the base station may not be divided intosectors. For example, if a coverage area of a base station antenna is 60degrees (°), the low-frequency wide beam sent by the base station may bedivided into four sectors, and a coverage area of each sector is 15°.Then the base station separately performs, in each sector with acoverage area of 15°, direction of arrival (DOA) estimation on a mobileterminal served by the base station. In addition, the low-frequency widebeam sent by the base station may not be divided into sectors, and alow-frequency wide beam with a coverage area of 60° is directly used.

In an embodiment of the present disclosure, after the base station andthe mobile terminal establish the low frequency channel, the mobileterminal may determine, according to a data traffic requirement, whetherto perform high frequency beam alignment of a high frequency antenna toestablish high frequency link synchronization. If the mobile terminaldetermines to establish high frequency link synchronization, the basestation may pre-determine an access right of the mobile terminal.Likewise, the mobile terminal may also pre-determine an access right ofthe base station in order to avoid an unnecessary high frequency antennaconnection.

Optionally, in an embodiment of the present disclosure, after the basestation and the mobile terminal establish the low frequency channel, themobile terminal and the base station may exchange high-frequencyfrequency information of the two parties using the low frequencychannel. In this way, complexity of high frequency beam alignment can bereduced, and high frequency beam alignment of a high frequency antennacan be further quickly implemented.

This embodiment of the present disclosure sets no limitation on aspecific method in step 204 in which the base station may perform highfrequency beam alignment of a high frequency antenna with the mobileterminal according to the scanning range of the high frequency beam. Forexample, the base station and the mobile terminal agree on a scanningstart time of the high frequency beam, a scanning sector division mannerof the high frequency beam, and a quantity of scanning sectors of thehigh frequency beam, and then the base station performs high frequencybeam alignment of high frequency antennas of the base station and themobile terminal according to first scanning information.

This embodiment of the present disclosure sets no limitation on a methodfor obtaining location information of the mobile terminal by the basestation using the low frequency channel. For example, the base stationmay receive, using the low frequency channel, the location informationof the mobile terminal that is determined using a global positioningsystem (GPS) and is sent by the mobile terminal. In addition, the basestation may further estimate a DOA of a low frequency beam using the lowfrequency channel in order to obtain DOA information of the lowfrequency beam, and determine the location information of the mobileterminal using the DOA information. After obtaining the locationinformation of the mobile terminal, the base station may determine thescanning range of the high frequency beam according to the locationinformation, and perform high frequency beam alignment of a highfrequency antenna according to the scanning range of the high frequencybeam. In this way, technical problems of a large scanning range and along beam alignment time that are caused by blind scanning performedwhen the base station does not exchange information with the mobileterminal can be avoided such that high frequency beam alignment of ahigh frequency antenna can be accelerated, and antenna beam alignmenttime can be shortened.

The base station may further receive, using the low frequency channel,the location information of the mobile terminal that is sent by themobile terminal, and then estimate the DOA of the low frequency beamusing the low frequency channel, to obtain the DOA information of thelow frequency beam. The base station may further narrow a range of thelocation information of the mobile terminal with reference to the DOAinformation. In this way, a scanning range of a beam can be furthernarrowed, and high frequency beam alignment of a high frequency antennacan be further accelerated.

The scanning range of the high frequency beam determined by the basestation according to the location information of the mobile terminal maybe as follows. The range of the location information of the mobileterminal is considered as the scanning range of the high frequency beam,or may be the scanning range of the high frequency beam is slightlylarger than the range of the location information of the mobileterminal. This is not limited in this embodiment of the presentdisclosure.

The following describes this embodiment of the present disclosure indetail with reference to specific examples. It should be noted thatthese examples are merely intended to help a person skilled in the artto better understand this embodiment of the present disclosure, but arenot intended to limit the scope of this embodiment of the presentdisclosure.

Optionally, in an embodiment of the present disclosure, performing highfrequency beam alignment of a high frequency antenna with thecommunications device according to the scanning range of the highfrequency beam includes sending M high-frequency narrow beams to thecommunications device according to the scanning range of the highfrequency beam, where each high-frequency narrow beam carries identity(ID) information used to indicate an ID of each high-frequency narrowbeam, and M is a positive integer, receiving a first ID, of a firsthigh-frequency narrow beam, that corresponds to a first maximumreceiving statistic and is sent by the communications device, where thefirst maximum receiving statistic is a maximum value in M receivingstatistics of received signals on the M high-frequency narrow beamsreceived by the communications device, and the first high-frequencynarrow beam is one of the M high-frequency narrow beams, sending thefirst high-frequency narrow beam to the communications device, andperforming high frequency beam alignment of a high frequency antennawith the communications device according to the first ID.

The mobile terminal initiates a high frequency link synchronizationconnection request after the base station and the mobile terminalestablish low frequency link synchronization. After receiving the highfrequency link synchronization connection request, the base stationfeeds back a high frequency link synchronization connection response tothe mobile terminal. If the base station consents to establish a highfrequency link synchronization connection, the base station mayestimate, using the low frequency channel, the DOA indicating adirection from which the low frequency beam arrives at the mobileterminal in order to obtain the DOA information of the low frequencybeam. The DOA information herein includes an estimated DOA range.Afterwards, the base station scans and sends M high-frequency narrowbeams at an angle in the estimated DOA range according to the DOAinformation. In addition, each high-frequency narrow beam carries IDinformation used to indicate an ID of each high-frequency narrow beam.Then, the mobile terminal receives, using a high-frequency wide beam (awide acceptance angle), the M high-frequency narrow beams sent by thebase station. After the mobile terminal receives the high-frequencynarrow beams, the mobile terminal parses IDs of the high-frequencynarrow beams. If the mobile terminal cannot obtain an ID of anyhigh-frequency narrow beam by means of parsing, the mobile terminalresends the high-frequency narrow beams in another direction range, andperforms searching and high frequency link synchronization in anotherdirection. If the mobile terminal can obtain the IDs of thehigh-frequency narrow beams by means of parsing, the mobile terminalthen calculates receiving statistics of received signals on all thehigh-frequency narrow beams, determines an ID of a high-frequency narrowbeam with a maximum receiving statistic, and denotes the ID as a firstID. Then, the mobile terminal sends the first ID to the base stationusing the low frequency channel, and denotes the high-frequency narrowbeam with a maximum receiving statistic as a first high-frequency narrowbeam. After receiving the first ID sent by the mobile terminal, the basestation sends the first high-frequency narrow beam to the mobileterminal. The mobile terminal receives the first high-frequency narrowbeam in different directions using G high-frequency narrow beams, andcalculates G receiving statistics of received signals on the Ghigh-frequency narrow beams to obtain an ID corresponding to ahigh-frequency narrow beam with a maximum receiving statistic in the Ghigh-frequency narrow beams, and denotes the ID as a second ID. Finally,the base station may perform high frequency beam alignment of a highfrequency antenna with the mobile terminal according to the first ID andthe second ID in order to establish high frequency link synchronization.

The first ID is an ID corresponding to a high-frequency narrow beam inthe M high-frequency narrow beams sent by the base station, where areceived signal on the high-frequency narrow beam has a maximumreceiving statistic, and the second ID is an ID corresponding to ahigh-frequency narrow beam in the G high-frequency narrow beams of themobile terminal, where a received signal on the high-frequency narrowbeam has a maximum receiving statistic.

The base station sends a high-frequency narrow beam to the mobileterminal, and the high-frequency narrow beam herein may be ahigh-frequency narrow beam in a low modulation mode. In this way, aprobability of synchronization between the base station and the mobileterminal can be increased, and low signal-to-noise ratio (SNR)communication between the base station and the mobile terminal can befurther implemented.

This embodiment of the present disclosure sets no limitation on thereceiving statistic. For example, the receiving statistic may be power,may be a received signal level (RSL), or may be an SNR. A person skilledin the art may design a receiving statistic in another form according toa requirement, and such design falls within the scope of this embodimentof the present disclosure as long as a designed receiving statistic canindicate signal strength or signal energy.

Before step 204, the base station and the mobile terminal may determinea scanning start time using the low frequency channel. The base stationand the mobile terminal determine to start scanning at a same moment(for example, 10 milliseconds (ms) later), and start to performhigh-frequency beam alignment of a high frequency antenna at thescanning start time. The scanning start time herein may be a first timeon which the base station and the mobile terminal agree, may be a secondtime sent by the base station to the mobile terminal using the lowfrequency channel, or may be a third time sent by the mobile terminal tothe base station using the low frequency channel. Any two of the firsttime, the second time, and the third time may be the same, or may bedifferent.

Optionally, in another embodiment of the present disclosure, for step204, the base station and the mobile terminal may agree on firstscanning information using the low frequency channel, and then performhigh frequency beam alignment between high frequency antennas of thebase station and the mobile terminal according to the scanning range ofthe high frequency beam and the first scanning information. The firstscanning information is used to indicate a scanning sector divisionmanner or a quantity of scanning sectors of the base station and ascanning sector division manner or a quantity of scanning sectors of themobile terminal. For example, the quantity of scanning sectors of themobile terminal is N, and the quantity of scanning sectors of the basestation is Q, N is a positive integer, and Q is a positive integer.

The Q scanning sectors of the base station are separately denoted as B₁,B₂, B₃, . . . , and B_(Q), and the N scanning sectors of the mobileterminal are separately denoted as U₁, U₂, U₃, . . . , and U_(N). Thebase station sends a high-frequency narrow beam to the mobile terminalin a first scanning sector according to the first scanning information,and the mobile terminal receives the high-frequency narrow beam in asecond scanning sector. The first scanning sector is any one of the Qscanning sectors, and the second scanning sector is any one of the Nscanning sectors. For example, the base station first sends ahigh-frequency narrow beam of the region B₁ to the mobile terminal inthe region B₁ according to the first scanning information, and thesending step lasts for a period of time T₁. The mobile terminalsuccessively receives, within T₁, the high-frequency narrow beam of theregion B₁ in each region of the regions U₁, U₂, U₃, . . . , and U_(N).Afterwards, the base station sends a high-frequency narrow beam of theregion B₂ to the mobile terminal in the region B₂, and the sending steplasts for a period of time T₁. The mobile terminal separately andsuccessively receives, within T₁, the high-frequency narrow beam of theregion B₂ in U₁, U₂, U₃, . . . , and U_(N). In this way, the basestation successively sends Q high-frequency narrow beams to the mobileterminal in the regions B₁, B₂, B₃, . . . , and B_(Q). The mobileterminal receives, using Q×N high-frequency narrow beams in total, the Qhigh-frequency narrow beams sent by the base station, determines Q×Nreceiving statistics of received signals on the Q×N high-frequencynarrow beams that are in a one-to-one correspondence with the Q scanningsectors and the N scanning sectors, and records the Q×N receivingstatistics in a Q×N matrix. Then, the mobile terminal sends a firstserial number q of the first scanning sector and a second serial numbern of the second scanning sector to the base station, where the firstserial number q and the second serial number n correspond to a maximumreceiving statistic in the Q×N receiving statistics. Finally, the basestation and the mobile terminal point a transmit beam and a receive beamto a direction of the maximum receiving statistic according to the firstserial number and the second serial number in order to perform highfrequency beam alignment of a high frequency antenna.

It should be understood that the Q high-frequency narrow beams sent inthe regions B₁, B₂, B₃, . . . , and B_(Q) may be a same high-frequencynarrow beam, or may be different high-frequency narrow beams. This isnot limited in this embodiment of the present disclosure.

For example, the first scanning information is that a base stationantenna is divided into ten sectors that are separately denoted as B₁,B₂, B₃, . . . , and B₁₀, and that a mobile terminal antenna is dividedinto five sectors that are separately denoted as U₁, U₂, U₃, . . . , andU₅. If a coverage area of the base station antenna is 120°, the basestation evenly divides the coverage area into ten sectors, and acoverage area of each sector antenna is 12°. Likewise, if a coveragearea of the mobile terminal antenna is 60°, the mobile terminal evenlydivides the coverage area into five sectors, and a coverage area of eachsector antenna is 12°. After using the low frequency channel, the basestation sends the first scanning information to the mobile terminal, orreceives the first scanning information sent by the mobile terminal, thebase station first sends a 12° high-frequency narrow beam to the mobileterminal at an angle (for example, an angle B₁), and the sending steplasts for 5 ms. Within the time of 5 ms during which the base stationcontinuously sends the 12° high-frequency narrow beam, the mobileterminal separately and successively receives, in the ranges U₁, U₂, U₃,. . . , and U₅, the 12° high-frequency narrow beam using ahigh-frequency narrow beam. That is, the mobile terminal first receivesthe high-frequency narrow beam at a 12° acceptance angle in a directionU₁, and the receiving step lasts for 1 ms. Then receives thehigh-frequency narrow beam at a 12° acceptance angle in a direction U₂,and the receiving step lasts for 1 ms, receives the high-frequencynarrow beam at a 12° acceptance angle in a direction U₃, and thereceiving step lasts for 1 ms, receives the high-frequency narrow beamat a 12° acceptance angle in a direction U₄, and the receiving steplasts for 1 ms, and receives the high-frequency narrow beam at a 12°acceptance angle in a direction U₅, and the receiving step lasts for 1ms. In addition, the mobile terminal records a power value at which asignal is received at each 1 ms using the high-frequency narrow beam.

Likewise, according to the foregoing method, the base station thensuccessively sends the 12° high-frequency narrow beam to the mobileterminal at angles B₂, B₃, and B₁₀, and the sending step lasts for 5 ms.Likewise, the mobile terminal separately and successively receives thehigh-frequency narrow beam in the ranges U₁, U₂, U₃, . . . , and U₅, andseparately receives the high-frequency narrow beam at a 12° acceptanceangle in the directions U₁, U₂, U₃, U₄, and U₅, and the receiving stepsrespectively lasts for 1 ms. In addition, the mobile terminal records apower value at which a signal is received at each 1 ms using thehigh-frequency narrow beam. In this way, it takes 50 ms to complete theforegoing cyclic process. After high-frequency narrow beam scanning ofthe base station and the mobile terminal ends, 50 (that is, 10×5) powervalues are obtained in total and denoted in a 10×5 matrix. The mobileterminal sends, to the base station using the low frequency channel, arow sequence number and a column sequence number that correspond to amatrix element with maximum power, that is, a first serial number of theten scanning sectors on the base station side and a second serial numberof the five scanning sectors on the mobile terminal side, where thefirst serial number and the second serial number correspond to thematrix element with maximum power. Alternatively, the mobile terminalsends a 10×5 matrix to the base station using the low frequency channel,and obtains, using the matrix, a first serial number of the ten scanningsectors on the base station side and a second serial number of the fivescanning sectors on the mobile terminal side, where the first serialnumber and the second serial number correspond to the matrix elementwith maximum power. Finally, the base station and the mobile terminalpoint the transmit beam and the receive beam to a direction of themaximum power according to the first serial number and the second serialnumber in order to perform high frequency beam alignment of a highfrequency antenna.

Therefore, in this embodiment of the present disclosure, a base stationand a mobile terminal agree on scanning information, and perform highfrequency beam alignment between high frequency antennas of the basestation and the mobile terminal according to the scanning information.In this way, a technical problem of a long beam alignment time that iscaused by blind scanning performed when the base station has notemporally synchronous handshake with the mobile terminal can be avoidedsuch that high frequency beam alignment of a high frequency antenna canbe accelerated.

It should be understood that in an embodiment of the present disclosure,when a serial number of a scanning sector is determined, description isprovided using only a scanning sector corresponding to maximum power asan example, or using another scanning sector corresponding to a maximumreceiving statistic such as an SNR or an RSL as an example. However, thepresent disclosure is not limited thereto.

In another embodiment of the present disclosure, after the mobileterminal sends, to the base station according to the foregoing methodusing the low frequency channel, the first serial number correspondingto the scanning sector on the base station side and the second serialnumber corresponding to the scanning sector on the mobile terminal side,where the first serial number and the second serial number correspond tothe matrix element with maximum power, or after the mobile terminalsends a Q×N matrix to the base station using the low frequency channel,the base station and the mobile terminal exchange, using the lowfrequency channel, information indicating that fine scanning continuesto be performed, that is, determine second scanning information. Forexample, the base station and the mobile terminal agree on a scanningsub-sector division manner or a quantity of scanning sub-sectors of ascanning sector corresponding to the first serial number and a scanningsub-sector division manner or a quantity of scanning sub-sectors of ascanning sector corresponding to the second serial number. It is assumedthat the quantity of scanning sub-sectors of the scanning sectorcorresponding to the first serial number is H, and the quantity ofscanning sub-sectors of the scanning sector corresponding to the secondserial number is P. The H scanning sub-sectors are separately denoted asB_(q1), B_(q2), B_(q3), . . . , and B_(qH), and the P scanningsub-sectors are separately denoted as U_(n1), U_(n2), U_(n3), . . . ,and U_(nP). The base station sends a high-frequency narrow beam to themobile terminal in a third scanning sector according to the secondscanning information, and the mobile terminal receives thehigh-frequency narrow beam in a fourth scanning sector. The thirdscanning sector is any one of the H scanning sub-sectors, and the fourthscanning sector is any one of the P scanning sub-sectors.

Further, the base station first sends a high-frequency narrow beam ofthe region B_(q1) to the mobile terminal in the region B_(q1) accordingto the second scanning information, and the sending step lasts for T₂.The mobile terminal separately receives, within T₂ in the regionsU_(n1), U_(n2), U_(n3), . . . , and U_(nP) using P high-frequency narrowbeams, the high-frequency narrow beam sent by the base station in theregion B_(q1). Afterwards, the base station sends a high-frequencynarrow beam of the region B_(q2) to the mobile terminal in the regionB_(q2). The mobile terminal separately receives, within T₂ in theregions U_(n1), U_(n2), U_(n3), . . . , and U_(nP) using Phigh-frequency narrow beams, the high-frequency narrow beam sent by thebase station in the region B_(q2). In such a sequence, the base stationfinally sends a high-frequency narrow beam of the region B_(qH) to themobile terminal in the region B_(qH). The mobile terminal separatelyreceives, within T₂ in the regions U_(n1), U_(n2), U_(n3), . . . , andU_(nP) using P high-frequency narrow beams, the high-frequency narrowbeam sent by the base station in the region B_(qH). The mobile terminalreceives, using H×P high-frequency narrow beams in total, Hhigh-frequency narrow beams sent by the base station in the H scanningsectors. After receiving the high-frequency narrow beams sent by thebase station, the mobile terminal determines H×P receiving statistics ofreceived signals on the H×P high-frequency narrow beams that are in aone-to-one correspondence with the third scanning sector and the fourthscanning sector, and records the H×P receiving statistics in an H×Pmatrix. Then, the mobile terminal sends a third serial number of thethird scanning sector and a fourth serial number of the fourth scanningsector to the base station, where the third serial number and the fourthserial number correspond to a maximum receiving statistic in the H×Preceiving statistics. Finally, the base station and the mobile terminalpoint the transmit beam and the receive beam to a direction of themaximum receiving statistic according to the third serial number and thefourth serial number in order to perform high frequency beam alignmentof a high frequency antenna.

In another embodiment of the present disclosure, in multiple scanningprocesses, the mobile terminal may perform high frequency beam alignmentof a high frequency antenna without determining a scanning sector with astrongest signal using a power detection method. For example, the basestation may send synchronization sequence information and a pilot. Themobile terminal determines whether the base station and the mobileterminal are synchronized, and obtains, according to a result of thedetermining, a serial number of a high-frequency narrow beam used forperforming high frequency beam alignment of a high frequency antenna, toperform high frequency beam alignment of a high frequency antenna. Ifthe mobile terminal obtains multiple synchronization sequences by meansof parsing, high-frequency narrow beams corresponding to the multiplesynchronization sequences are used as candidate high-frequency narrowbeams required for alignment. The base station and the mobile terminalselect an optimal high-frequency narrow beam from the candidatehigh-frequency narrow beams according to a priority, to perform highfrequency beam alignment of a high frequency antenna. If obtaining onlyone synchronization sequence by means of parsing, the base station andthe mobile terminal use a high-frequency narrow beam corresponding tothe synchronization sequence as a high-frequency narrow beam used foralignment in order to perform high frequency beam alignment of a highfrequency antenna. If the mobile terminal obtains no synchronizationsequence by means of parsing, the base station and the mobile terminalcannot be synchronized.

The base station and the mobile terminal may perform scanning multipletimes using the low frequency channel. The base station may graduallynarrow a location range of the mobile terminal by performing multipletimes of scanning, and exchange result information of the multiple timesof scanning using the low frequency channel. In this way, accuracy ofhigh frequency beam alignment can be improved, and establishment of highfrequency link synchronization can be accelerated. Description isprovided herein using only two times of scanning as an example. However,the present disclosure is not limited thereto.

This embodiment of the present disclosure sets no limitation on thereceiving statistic. For example, the receiving statistic may be atleast one of power, an SNR, or an RSL.

The method for aligning antenna beams in a high-low frequency co-sitenetwork according to this embodiment of the present disclosure isdescribed in detail above from a perspective of a base station withreference to FIG. 2. The following describes a method for aligningantenna beams in a high-low frequency co-site network according to anembodiment of the present disclosure from a perspective of a mobileterminal with reference to FIG. 3.

FIG. 3 is a schematic flowchart of a method for aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure. The method in FIG. 3 may be executed by asecond communications device (for example, the mobile terminal 103 inFIG. 1).

Step 301: Establish a low frequency channel with a low frequency antennaof a communications device, where the communications device may be abase station, such as the base station 101 in FIG. 1.

Step 302: Obtain location information of the communications device usingthe low frequency channel.

Step 303: Determine a scanning range of a high frequency beam accordingto the location information of the communications device.

Step 304: Perform high frequency beam alignment of a high frequencyantenna with the communications device according to the scanning rangeof the high frequency beam.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time of a high frequency antenna is long due toa narrow field of view of a high frequency beam can be avoided such thathigh frequency beam alignment of a high frequency antenna can be quicklyimplemented.

Description is provided herein using an example in which a firstcommunications device is a base station, such as the base station 101 inthe FIG. 1, and a second communications device is a mobile terminal,such as the mobile terminal 103 in FIG. 1. However, the presentdisclosure is not limited thereto.

In step 301, the mobile terminal scans a low frequency beam of the basestation using a low-frequency wide beam to search for a target cell, andthen completes procedures such as symbol-level timing detection, radioframe clock detection, and cell ID detection on the low frequencychannel, to complete low frequency link synchronization.

Further, the mobile terminal scans, sends, and receives thelow-frequency wide beam of the base station to search for a target cellin order to obtain downlink synchronization information of the targetcell and related configuration information of the target cell. Themobile terminal that is just powered on can obtain information such astime-frequency synchronization and a cell ID of an optimal target cellonly after the mobile terminal initiates a cell search command, and themobile terminal may receive system information after completing cellsearch. Afterwards, the mobile terminal detects a physicalsynchronization channel (PSCH), a secondary synchronization channel(SSCH), a downlink reference signal, and the like to complete theprocedures such as symbol-level timing detection, radio frame clockdetection, and cell ID detection. After completing the detectionprocedures, the mobile terminal may detect a public land mobile network(PLMN) identifier from the system information, select a cell accordingto the PLMN identifier, and complete low frequency link synchronizationbetween the base station and the mobile terminal in order to establishthe low frequency channel.

In an embodiment of the present disclosure, after the base station andthe mobile terminal establish the low frequency channel, the mobileterminal may determine, according to a data traffic requirement, whetherto perform high frequency beam alignment of a high frequency antenna toestablish high frequency link synchronization. If the mobile terminaldetermines to establish high frequency link synchronization, the basestation may pre-determine an access right of the mobile terminal.Likewise, the mobile terminal may also pre-determine an access right ofthe base station, to avoid an unnecessary high frequency antennaconnection.

Optionally, in an embodiment of the present disclosure, after the basestation and the mobile terminal establish the low frequency channel, themobile terminal and the base station may exchange high-frequencyfrequency information of the two parties using the low frequencychannel. In this way, complexity of high frequency beam alignment can bereduced, and high frequency beam alignment of a high frequency antennacan be further quickly implemented.

This embodiment of the present disclosure sets no limitation on a methodfor obtaining the location information of the communications device. Forexample, the location information of the communications device that isdetermined using a GPS and is sent by the communications device may bereceived using the low frequency channel.

The following describes this embodiment of the present disclosure indetail with reference to specific examples. It should be noted thatthese examples are merely intended to help a person skilled in the artto better understand this embodiment of the present disclosure, but arenot intended to limit the scope of this embodiment of the presentdisclosure.

Optionally, in an embodiment of the present disclosure, performing highfrequency beam alignment of a high frequency antenna with thecommunications device according to the scanning range of the highfrequency beam includes receiving M high-frequency narrow beams sent bythe communications device, where each high-frequency narrow beam carriesID information used to indicate an ID of each high-frequency narrowbeam, determining M receiving statistics that are of received signals onthe high-frequency narrow beams and correspond to the M high-frequencynarrow beams, sending, to the communications device, a first ID that isof a first high-frequency narrow beam and corresponds to a first maximumreceiving statistic, where the first maximum receiving statistic is amaximum value in the M receiving statistics, and the firsthigh-frequency narrow beam is one of the M high-frequency narrow beams,receiving, using G high-frequency narrow beams, the first high-frequencynarrow beam sent by the communications device, determining a second IDof a high-frequency narrow beam in the G high-frequency narrow beams,where a received signal on the high-frequency narrow beam has a maximumreceiving statistic, and performing high frequency beam alignment of ahigh frequency antenna with the communications device according to thefirst ID and the second ID.

For example, after the mobile terminal and the base station establishlow frequency link synchronization, the mobile terminal sends a highfrequency link synchronization connection request to the base station,and receives a high frequency link synchronization connection responsefed back by the base station. When receiving the connection responsethat is sent by the base station and indicates that the base stationconsents to establish high frequency link synchronization, the mobileterminal receives, using a low-frequency wide beam (a wide acceptanceangle), M high-frequency narrow beams sent by the base station. Itshould be understood that the mobile terminal may receive thehigh-frequency narrow beams at a sector angle, or may receive thehigh-frequency narrow beams using an omnidirectional antenna. After themobile terminal receives the high-frequency narrow beams, the mobileterminal parses IDs of the high-frequency narrow beams. If the mobileterminal cannot obtain an ID of any high-frequency narrow beam by meansof parsing, the mobile terminal resends the high-frequency narrow beamsin another direction range, and performs searching and high frequencylink synchronization in another direction. If the mobile terminal canobtain the IDs of the high-frequency narrow beams by means of parsing,the mobile terminal then calculates receiving statistics of receivedsignals on all the high-frequency narrow beams, determines an ID of ahigh-frequency narrow beam with a maximum receiving statistic, anddenotes the ID as a first ID. Then, the mobile terminal sends the firstID to the base station using the low frequency channel, and denotes thehigh-frequency narrow beam with a maximum receiving statistic as a firsthigh-frequency narrow beam. The mobile terminal receives the firsthigh-frequency narrow beam sent by the base station according to thefirst ID. The mobile terminal receives the first high-frequency narrowbeam in different directions using G high-frequency narrow beams, andcalculates G receiving statistics of receives signal on the Ghigh-frequency narrow beams to obtain an ID corresponding to ahigh-frequency narrow beam in the G high-frequency narrow beams, where areceived signal on the high-frequency narrow beam has a maximumreceiving statistic, and denotes the ID as a second ID. Finally, themobile terminal may perform high frequency beam alignment of a highfrequency antenna with the base station according to the first ID andthe second ID in order to establish high frequency link synchronization.

The first ID is an ID corresponding to a high-frequency narrow beam inthe M high-frequency narrow beams sent by the base station, where areceived signal on the high-frequency narrow beam has a maximumreceiving statistic, and the second ID is an ID corresponding to ahigh-frequency narrow beam in the G high-frequency narrow beams of themobile terminal, where a received signal on the high-frequency narrowbeam has a maximum receiving statistic.

This embodiment of the present disclosure sets no limitation on thereceiving statistic. For example, the receiving statistic may be power,may be an RSL, or may be an SNR. A person skilled in the art may designa receiving statistic in another form according to a requirement, andsuch design falls within the scope of this embodiment of the presentdisclosure as long as a designed receiving statistic can indicate signalstrength or signal energy.

Optionally, the base station and the mobile terminal may determine ascanning start time using the low frequency channel. The base stationand the mobile terminal determine to start scanning at a same moment(for example, 10 ms later), and start to perform high-frequency beamalignment of a high frequency antenna at the scanning start time. Thescanning start time herein may be a first time on which the base stationand the mobile terminal agree, may be a second time sent by the basestation to the mobile terminal using the low frequency channel, or maybe a third time sent by the mobile terminal to the base station usingthe low frequency channel. Any two of the first time, the second time,and the third time may be the same, or may be different.

Optionally, in another embodiment of the present disclosure, the mobileterminal and the base station may agree on first scanning informationusing the low frequency channel, and then perform high frequency beamalignment between high frequency antennas of the base station and themobile terminal according to the scanning range of the high frequencybeam and the first scanning information. The first scanning informationis used to indicate a scanning sector division manner or a quantity ofscanning sectors of the base station and a scanning sector divisionmanner or a quantity of scanning sectors of a mobile device. Forexample, the quantity of scanning sectors of the mobile terminal is N,and the quantity of scanning sectors of the base station is Q, N is apositive integer, and Q is a positive integer.

The Q scanning sectors of the base station are separately denoted as B₁,B₂, B₃, . . . , and B_(Q), and the N scanning sectors of the mobileterminal are separately denoted as U₁, U₂, U₃, . . . , and U_(N). Thebase station sends a high-frequency narrow beam to the mobile terminalin a first scanning sector according to the first scanning information,and the mobile terminal receives the high-frequency narrow beam in asecond scanning sector. The first scanning sector is any one of the Qscanning sectors, and the second scanning sector is any one of the Nscanning sectors. For example, the base station first sends ahigh-frequency narrow beam of the region B₁ to the mobile terminal inthe region B₁ according to the first scanning information, and thesending step lasts for a period of time T₁. The mobile terminalsuccessively receives, within T₁, the high-frequency narrow beam of theregion B₁ in each region of the regions U₁, U₂, U₃, . . . , and U_(N).Afterwards, the base station sends a high-frequency narrow beam of theregion B₂ to the mobile terminal in the region B₂, and the sending steplasts for a period of time T₁. The mobile terminal separately andsuccessively receives, within T₁, the high-frequency narrow beam of theregion B₂ in U₁, U₂, U₃, . . . , and U_(N). In this way, the basestation successively sends Q high-frequency narrow beams to the mobileterminal in the regions B₁, B₂, B₃, . . . , and B_(Q). The mobileterminal receives, using Q×N high-frequency narrow beams in total, the Qhigh-frequency narrow beams sent by the base station, determines Q×Nreceiving statistics of received signals on the Q×N high-frequencynarrow beams that are in a one-to-one correspondence with the Q scanningsectors and the N scanning sectors, and records the Q×N receivingstatistics in a Q×N matrix. Then, the mobile terminal sends a firstserial number q of the first scanning sector and a second serial numbern of the second scanning sector to the base station, where the firstserial number q and the second serial number n correspond to a maximumreceiving statistic in the Q×N receiving statistics. Finally, the basestation and the mobile terminal point a transmit beam and a receive beamto a direction of the maximum receiving statistic according to the firstserial number and the second serial number, to perform high frequencybeam alignment of a high frequency antenna.

It should be understood that the Q high-frequency narrow beams sent inthe regions B₁, B₂, B₃, . . . , and B_(Q) may be a same high-frequencynarrow beam, or may be different high-frequency narrow beams. This isnot limited in this embodiment of the present disclosure.

For example, the first scanning information is that a base stationantenna is divided into ten sectors that are separately denoted as B₁,B₂, B₃, . . . , and B₁₀ and that a mobile terminal antenna is dividedinto five sectors that are separately denoted as U₁, U₂, U₃ . . . . If acoverage area of the base station antenna is 120°, the base stationevenly divides the coverage area into ten sectors, and a coverage areaof each sector antenna is 12°. Likewise, if a coverage area of themobile terminal antenna is 60°, the mobile terminal evenly divides thecoverage area into five sectors, and a coverage area of each sectorantenna is 12°. After using the low frequency channel, the base stationsends the first scanning information to the mobile terminal, or receivesthe first scanning information sent by the mobile terminal, the basestation first sends a 12° high-frequency narrow beam to the mobileterminal at an angle (for example, an angle B₁), and the sending steplasts for 5 ms. Within the time of 5 ms during which the base stationcontinuously sends the 12° high-frequency narrow beam, the mobileterminal separately and successively receives, in the ranges U₁, U₂, U₃,. . . , and U₅, the 12° high-frequency narrow beam using ahigh-frequency narrow beam. That is, the mobile terminal first receivesthe high-frequency narrow beam at a 12° acceptance angle in a directionU₁, and the receiving step lasts for 1 ms. Then receives thehigh-frequency narrow beam at a 12° acceptance angle in a direction U₂,and the receiving step lasts for 1 ms, receives the high-frequencynarrow beam at a 12° acceptance angle in a direction U₃, and thereceiving step lasts for 1 ms, receives the high-frequency narrow beamat a 12° acceptance angle in a direction U₄, and the receiving steplasts for 1 ms, and receives the high-frequency narrow beam at a 12°acceptance angle in a direction U₅, and the receiving step lasts for 1ms. In addition, the mobile terminal records a power value at which asignal is received at each 1 ms using the high-frequency narrow beam.

Likewise, according to the foregoing method, the base station thensuccessively sends the 12° high-frequency narrow beam to the mobileterminal at angles B₂, B₃, . . . , and B₁₀, and the sending step lastsfor 5 ms. Likewise, the mobile terminal separately and successivelyreceives the high-frequency narrow beam in the ranges U₁, U₂, U₃, . . ., and U₅, and separately receives the high-frequency narrow beam at a12° acceptance angle in the directions U₁, U₂, U₃, U₄, and U₅, and thereceiving steps respectively lasts for 1 ms. In addition, the mobileterminal records a power value at which a signal is received at each 1ms using the high-frequency narrow beam. In this way, it takes 50 ms tocomplete the foregoing cyclic process. After high-frequency narrow beamscanning of the base station and the mobile terminal ends, 50 (that is,10×5) power values are obtained in total and denoted in a 10×5 matrix.The mobile terminal sends, to the base station using the low frequencychannel, a row sequence number and a column sequence number thatcorrespond to a matrix element with maximum power, that is, a firstserial number of the ten scanning sectors on the base station side and asecond serial number of the five scanning sectors on the mobile terminalside, where the first serial number and the second serial numbercorrespond to the matrix element with maximum power. Alternatively, themobile terminal sends a 10×5 matrix to the base station using the lowfrequency channel, and obtains, using the matrix, a first serial numberof the ten scanning sectors on the base station side and a second serialnumber of the five scanning sectors on the mobile terminal side, wherethe first serial number and the second serial number correspond to thematrix element with maximum power. Finally, the base station and themobile terminal point the transmit beam and the receive beam to adirection of the maximum power according to the first serial number andthe second serial number in order to perform high frequency beamalignment of a high frequency antenna.

Therefore, in this embodiment of the present disclosure, a base stationand a mobile terminal agree on scanning information, and perform highfrequency beam alignment between high frequency antennas of the basestation and the mobile terminal according to the scanning information.In this way, a technical problem of a long beam alignment time that iscaused by blind scanning performed when the base station has notemporally synchronous handshake with the mobile terminal can be avoidedsuch that high frequency beam alignment of a high frequency antenna canbe accelerated.

It should be understood that in an embodiment of the present disclosure,when a serial number of a scanning sector is determined, description isprovided using only a scanning sector corresponding to maximum power asan example, or using another scanning sector corresponding to a maximumreceiving statistic such as an SNR or an RSL as an example. However, thepresent disclosure is not limited thereto.

In another embodiment of the present disclosure, after the mobileterminal sends, to the base station according to the foregoing methodusing the low frequency channel, the first serial number correspondingto the scanning sector on the base station side and the second serialnumber corresponding to the scanning sector on the mobile terminal side,where the first serial number and the second serial number correspond tothe matrix element with maximum power, or after the mobile terminalsends a Q×N matrix to the base station using the low frequency channel,the mobile terminal and the base station may exchange, using the lowfrequency channel, information indicating that fine scanning continuesto be performed, that is, agree on second scanning information. Forexample, the base station and the mobile terminal agree on secondscanning information, for example, agree on a scanning sub-sectordivision manner or a quantity of scanning sub-sectors of a scanningsector corresponding to the first serial number and a scanningsub-sector division manner or a quantity of scanning sub-sectors of ascanning sector corresponding to the second serial number. It is assumedthat the quantity of scanning sub-sectors of the scanning sectorcorresponding to the first serial number is H, and the quantity ofscanning sub-sectors of the scanning sector corresponding to the secondserial number is P. The H scanning sub-sectors are separately denoted asB_(q1), B_(q2), B_(q3), . . . , and B_(qH), and the P scanningsub-sectors are separately denoted as U_(n1), U_(n2), U_(n3), . . . ,and U_(nP). The base station sends a high-frequency narrow beam to themobile terminal in a third scanning sector according to the secondscanning information, and the mobile terminal receives thehigh-frequency narrow beam in a fourth scanning sector. The thirdscanning sector is any one of the H scanning sub-sectors, and the fourthscanning sector is any one of the P scanning sub-sectors.

Further, the base station first sends a high-frequency narrow beam ofthe region B_(q1) to the mobile terminal in the region B_(q1) accordingto the second scanning information, and the sending step lasts for T₂.The mobile terminal separately receives, within T₂ in the regions U_(n1)U_(n2), U_(n3), . . . , and U_(nP) using P high-frequency narrow beams,the high-frequency narrow beam sent by the base station in the regionB_(q1). Afterwards, the base station sends a high-frequency narrow beamof the region B_(q2) to the mobile terminal in the region B_(q2). Themobile terminal separately receives, within T₂ in the regions U_(n1),U_(n2), U_(n3), . . . , and U_(nP) using P high-frequency narrow beams,the high-frequency narrow beam sent by the base station in the regionB_(q2). In such a sequence, the base station finally sends ahigh-frequency narrow beam of the region B_(qH) to the mobile terminalin the region B_(qH). The mobile terminal separately receives, within T₂in the regions U_(n1) U_(n2), U_(n3), . . . , and U_(nP) using Phigh-frequency narrow beams, the high-frequency narrow beam sent by thebase station in the region B_(qH). The mobile terminal receives, usingH×P high-frequency narrow beams in total, H high-frequency narrow beamssent by the base station in the H scanning sectors. After receiving thehigh-frequency narrow beams sent by the base station, the mobileterminal determines H×P receiving statistics of received signals on theH×P high-frequency narrow beams that are in a one-to-one correspondencewith the third scanning sector and the fourth scanning sector, andrecords the H×P receiving statistics in an H×P matrix. Then, the mobileterminal sends a third serial number of the third scanning sector and afourth serial number of the fourth scanning sector to the base station,where the third serial number and the fourth serial number correspond toa maximum receiving statistic in the H×P receiving statistics. Finally,the base station and the mobile terminal point the transmit beam and thereceive beam to a direction of the maximum receiving statistic accordingto the third serial number and the fourth serial number, to perform highfrequency beam alignment of a high frequency antenna.

In another embodiment of the present disclosure, in multiple scanningprocesses, the mobile terminal may perform high frequency beam alignmentof a high frequency antenna without determining a scanning sector with astrongest signal using a power detection method. For example, the basestation may send synchronization sequence information and a pilot. Themobile terminal determines whether the base station and the mobileterminal are synchronized, and obtains, according to a result of thedetermining, a serial number of a high-frequency narrow beam used forperforming high frequency beam alignment of a high frequency antenna, toperform high frequency beam alignment of a high frequency antenna. Ifthe mobile terminal obtains multiple synchronization sequences by meansof parsing, high-frequency narrow beams corresponding to the multiplesynchronization sequences are used as candidate high-frequency narrowbeams required for alignment. The base station and the mobile terminalselect an optimal high-frequency narrow beam from the candidatehigh-frequency narrow beams according to a priority, to perform highfrequency beam alignment of a high frequency antenna. If obtaining onlyone synchronization sequence by means of parsing, the base station andthe mobile terminal use a high-frequency narrow beam corresponding tothe synchronization sequence as a high-frequency narrow beam used foralignment, to perform high frequency beam alignment of a high frequencyantenna. If the mobile terminal obtains no synchronization sequence bymeans of parsing, the base station and the mobile terminal cannot besynchronized.

The mobile terminal and the base station may perform scanning multipletimes using the low frequency channel. The base station may graduallynarrow a location range of the mobile terminal by performing multipletimes of scanning, and exchange result information of the multiple timesof scanning using the low frequency channel. In this way, accuracy ofhigh frequency beam alignment can be improved, and establishment of highfrequency synchronization can be accelerated. Description is providedherein using only two times of scanning as an example. However, thepresent disclosure is not limited thereto.

The following describes detailed procedures of the embodiments of thepresent disclosure with reference to FIG. 4 to FIG. 7. FIG. 4 is aschematic flowchart of a process of aligning antenna beams in a high-lowfrequency co-site network according to an embodiment of the presentdisclosure.

Step 401: A mobile terminal scans a low frequency beam of a base stationusing a low-frequency wide beam.

In step 401, the mobile terminal receives, using the low-frequency widebeam, the low frequency beam sent by the base station. The mobileterminal scans, sends, and receives the low-frequency wide beam of thebase station to search for a target cell, to obtain downlinksynchronization information of the target cell and related configurationinformation of the target cell. The mobile terminal that is just poweredon can obtain information such as time-frequency synchronization and acell ID of an optimal target cell only after the mobile terminalinitiates a cell search command, and the mobile terminal may receivesystem information after completing cell search.

Step 402: Determine whether the mobile terminal finds the low frequencybeam of the base station.

In step 402, it is determined whether the mobile terminal finds the lowfrequency beam sent by the base station. If the mobile terminal findsthe low frequency beam sent by the base station, the mobile terminalperforms step 403, and if the mobile terminal does not find the lowfrequency beam sent by the base station, the mobile terminal returns tostep 401 to perform re-scanning.

It should be understood that a low-frequency wide beam sent by the basestation may be divided into multiple sectors using an existing beamforming technology, and each sector covers an angle. Alternatively, alow-frequency wide beam sent by the base station may not be divided intosectors. For example, if a coverage area of a base station antenna is60°, the low-frequency wide beam sent by the base station may be dividedinto four sectors, and a coverage area of each sector is 15°. Then thebase station separately performs, in each sector with a coverage area of15°, DOA estimation on a mobile terminal served by the base station. Inaddition, the low-frequency wide beam sent by the base station may notbe divided into sectors, and a low-frequency wide beam with a coveragearea of 60° is directly used.

Step 403: Complete low frequency link synchronization to establish a lowfrequency channel.

The mobile terminal detects a PSCH, an SSCH, a downlink referencesignal, and the like, to complete procedures such as symbol-level timingdetection, radio frame clock detection, and cell ID detection. Aftercompleting the detection procedures, the mobile terminal may detect aPLMN identifier from the system information, and complete low frequencylink synchronization between the base station and the mobile terminalaccording to the PLMN identifier to establish the low frequency channel.

In an embodiment of the present disclosure, after the base station andthe mobile terminal establish the low frequency channel, the mobileterminal may determine, according to a data traffic requirement, whetherto perform high frequency beam alignment of a high frequency antenna toestablish high frequency link synchronization. If the mobile terminaldetermines to establish high frequency link synchronization, the basestation may pre-determine an access right of the mobile terminal.Likewise, the mobile terminal may also pre-determine an access right ofthe base station, to avoid an unnecessary high frequency antennaconnection.

Optionally, in another embodiment of the present disclosure, after thebase station and the mobile terminal establish the low frequencychannel, the mobile terminal and the base station may exchangehigh-frequency frequency information of the two parties using the lowfrequency channel. In this way, complexity of high frequency beamalignment can be reduced, and high frequency beam alignment of a highfrequency antenna can be further quickly implemented.

Step 404: The base station estimates a DOA using the low frequencychannel in order to obtain DOA information.

After the mobile terminal and the base station complete low frequencylink synchronization, the mobile terminal initiates a high frequencylink synchronization connection request. After receiving the highfrequency link synchronization connection request, the base stationfeeds back a high frequency link synchronization connection response.Afterwards, the base station estimates, using the low frequency channel,the DOA indicating a direction from which the low frequency beam arrivesat the mobile terminal, to obtain the DOA information.

Optionally, in an embodiment of the present disclosure, before step 404,the base station may estimate a location of the mobile terminal usingthe low frequency channel in order to obtain location information of themobile terminal. For example, the mobile terminal may determine thelocation information of the mobile terminal using a GPS, and send thelocation information to the base station. In this way, the base stationmay narrow a scanning and sending range of a high frequency beam usingthe location information of the mobile terminal. Likewise, the basestation may also determine location information of the base stationusing the GPS, and send the location information to the mobile terminal.In this way, the mobile terminal may narrow a scanning and receivingrange of the high frequency beam using the location information of thebase station. Therefore, the base station and the mobile terminalexchange the location information using the GPS such that a scanning andsending/receiving range of a high frequency beam can be furthernarrowed, a high frequency beam alignment time of a high frequencyantenna can be shorten, and high frequency link synchronization can bequickly completed.

Step 405: The base station and the mobile terminal perform highfrequency beam alignment using the DOA information.

The DOA information includes a DOA estimation range. The base stationand the mobile terminal perform beam scanning, sending, and receiving inthe DOA estimation range, and calculate beam power to determine anantenna alignment direction. Finally, the base station and the mobileterminal point a beam to a direction in which power of the highfrequency beam is maximum in order to perform high frequency beamalignment of a high frequency antenna.

Step 406: Determine whether high frequency beams are aligned.

Step 407: Start to transmit high frequency data.

Step 408: Perform searching and high frequency beam alignment in anotherdirection.

Step 409: Determine whether high frequency beams are aligned.

In step 406, the base station may send a synchronization sequence to themobile terminal. The mobile terminal parses the synchronization sequenceafter receiving the synchronization sequence sent by the base station todetermine whether high frequency beams of the base station and themobile terminal has been aligned. If the base station and the mobileterminal are synchronized, high frequency beam alignment can becompleted. If the mobile terminal obtains multiple synchronizationsequences by means of parsing, high-frequency narrow beams correspondingto the multiple synchronization sequences are used as candidatehigh-frequency narrow beams required for alignment. The base station andthe mobile terminal select an optimal high-frequency narrow beam fromthe candidate high-frequency narrow beams according to a priority inorder to perform high frequency beam alignment of a high frequencyantenna. If obtaining only one synchronization sequence by means ofparsing, the base station and the mobile terminal use a high-frequencynarrow beam corresponding to the synchronization sequence as ahigh-frequency narrow beam used for alignment to perform high frequencybeam alignment of a high frequency antenna. If the base station and themobile terminal cannot be synchronized, the high frequency beams of highfrequency antennas are not aligned.

If the high frequency beams of the high frequency antennas of the basestation and the mobile terminal have been aligned, step 407 isperformed, that is, the base station and the mobile terminal may startto transmit high frequency data.

If the high frequency beams of the high frequency antennas of the basestation and the mobile terminal are not aligned, step 408 is performed,that is, the base station and the mobile terminal perform searching andhigh frequency beam alignment in another direction. Afterwards, step 409is performed, that is, it is determined again whether the high frequencybeams are aligned. If the high frequency beams of the high frequencyantennas of the base station and the mobile terminal have been aligned,step 407 is performed, that is, the base station and the mobile terminalstart to transmit high frequency data. If the high frequency beams ofthe high frequency antennas of the base station and the mobile terminalare not aligned, the procedure ends.

It should be understood that in another embodiment of the presentdisclosure, if the base station serves multiple mobile terminals,parallel search for the multiple users and the base station may beimplemented in the present disclosure. Likewise, for a high frequencybeam, high frequency beam scanning, sending, and receiving may also beperformed on both the base station and the mobile terminal thatcompletes DOA estimation to perform high frequency beam alignment of ahigh frequency antenna and establish high frequency linksynchronization.

FIG. 5 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure. The following describes the process in step405 in which the base station and the mobile terminal perform highfrequency beam alignment using the DOA information.

Step 501: The base station sends M high-frequency narrow beams in anestimated DOA range.

The base station sends the M high-frequency narrow beams at an angle inan estimated DOA range according to DOA information. In addition, eachhigh-frequency narrow beam carries ID information used to indicate an IDof each high-frequency narrow beam.

Step 502: The mobile terminal receives the M high-frequency narrowbeams.

The mobile terminal receives, using a low-frequency wide beam (a wideacceptance angle), the M high-frequency narrow beams sent by the basestation. The mobile terminal may receive the high-frequency narrow beamsat a sector angle, or may receive the M high-frequency narrow beamsusing an omnidirectional antenna.

Step 503: Determine whether the mobile terminal obtains ID numbers ofthe M high-frequency narrow beams by means of parsing.

Step 504: Perform searching and synchronization in another direction.

After the mobile terminal receives the high-frequency narrow beams, themobile terminal parses the IDs of the high-frequency narrow beams, andthen performs step 503. If the mobile terminal cannot obtain an ID ofany high-frequency narrow beam by means of parsing, the mobile terminalperforms step 504, that is, the mobile terminal resends thehigh-frequency narrow beams in another direction range, and performssearching and high frequency link synchronization in another direction.

Step 505: The mobile terminal calculates power of the high-frequencynarrow beams, and sends, to the base station using a low frequencychannel, a first ID of a high-frequency narrow beam corresponding tomaximum power.

After the mobile terminal receives the high-frequency narrow beams, themobile terminal parses the IDs of the high-frequency narrow beams, andthen performs step 503. If the mobile terminal can obtain the IDs of thehigh-frequency narrow beams by means of parsing, the mobile terminalperforms step 505, that is, the mobile terminal calculates power of allthe received high-frequency narrow beams, determines an ID of ahigh-frequency narrow beam with maximum power, and denotes the ID as thefirst ID.

Step 506: The base station sends, according to the first ID, thehigh-frequency narrow beam corresponding to the maximum power.

The mobile terminal sends the first ID to the base station using the lowfrequency channel, and denotes the high-frequency narrow beam withmaximum power as a first high-frequency narrow beam.

Step 507: The mobile terminal receives, using G high-frequency narrowbeams, the high-frequency narrow beams sent by the base station, andobtains, by means of parsing, a second ID of a high-frequency narrowbeam with maximum power in the G high-frequency narrow beams.

After receiving the first ID sent by the mobile terminal, the basestation sends the first high-frequency narrow beam to the mobileterminal. The mobile terminal receives the first high-frequency narrowbeam in different directions using the G high-frequency narrow beams,calculates power of the G high-frequency narrow beams to obtain the IDcorresponding to the high-frequency narrow beam with maximum power inthe G high-frequency narrow beams, and denotes the ID as the second ID.

Step 508: The base station and the mobile terminal perform highfrequency beam alignment according to the first ID and the second ID.

The base station and the mobile terminal may perform high frequency beamalignment of a high frequency antenna according to the first ID and thesecond ID in order to establish high frequency link synchronization. Thebase station and the mobile terminal may point the high-frequency narrowbeams to directions of the first ID and the second ID to perform highfrequency beam alignment of a high frequency antenna. The first ID isthe ID corresponding to the high-frequency narrow beam with maximumpower in the M high-frequency narrow beams sent by the base station, andthe second ID is the ID corresponding to the high-frequency narrow beamin the G high-frequency narrow beams of the mobile terminal, where areceived signal on the high-frequency narrow beam has a maximum receivepower.

It should be understood that in this embodiment of the presentdisclosure, an ID of a high-frequency narrow beam required for highfrequency antenna alignment may be determined using power, or an ID of arequired high-frequency narrow beam may be determined using an SNR or anRSL. However, the present disclosure is not limited thereto. A personskilled in the art may design a receiving statistic in another formaccording to a requirement, and such design falls within the scope ofthis embodiment of the present disclosure as long as a designedreceiving statistic can indicate signal strength or signal energy.

FIG. 6 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure.

Step 601: A base station and a mobile terminal perform low frequencylink synchronization.

The mobile terminal scans and receives, using a low-frequency wide beam,a low frequency beam sent by the base station. The mobile terminalscans, sends, and receives the low-frequency wide beam of the basestation to search for a target cell in order to obtain downlinksynchronization information of the target cell and related configurationinformation of the target cell. The mobile terminal that is just poweredon can obtain information such as time-frequency synchronization and acell ID of an optimal target cell only after the mobile terminalinitiates a cell search command, and the mobile terminal may receivesystem information after completing cell search.

The mobile terminal detects a PSCH, an SSCH, a downlink referencesignal, and the like in order to complete procedures such assymbol-level timing detection, radio frame clock detection, and cell IDdetection. After completing the detection procedures, the mobileterminal may detect a PLMN identifier from the system information, andcomplete low frequency link synchronization between the base station andthe mobile terminal according to the PLMN identifier in order toestablish a low frequency channel.

Step 602: Determine whether low frequency link synchronization iscompleted.

The base station and the mobile terminal determine whether low frequencylink synchronization is completed, and if low frequency linksynchronization is not completed, return to step 601 to continue toperform low frequency synchronization.

Step 603: The mobile terminal requests to establish high frequency linksynchronization.

The base station and the mobile terminal determine whether low frequencylink synchronization is completed, and perform step 603 if low frequencylink synchronization is completed. The mobile terminal determines,according to a data traffic requirement, whether to establish highfrequency link synchronization, and performs step 607 if there is noneed to establish high frequency link synchronization.

Step 604: Perform mutual authentication or exchange high-frequencyfrequency information using a low frequency channel.

If there is a need to establish high frequency link synchronization,step 604 is performed. The base station and the mobile terminaldetermine whether to perform mutual authentication or to confirmhigh-frequency frequency information of the two parties. If there is noneed to establish high frequency link synchronization, step 607 isperformed. If there is a need to establish high frequency linksynchronization, the base station and the mobile terminal perform mutualauthentication or confirm the high-frequency frequency information ofthe two parties, and then perform step 605.

Optionally, if the mobile terminal determines to establish highfrequency link synchronization, the base station may pre-determine anaccess right of the mobile terminal. Likewise, the mobile terminal mayalso pre-determine an access right of the base station in order to avoidan unnecessary high frequency antenna connection.

Optionally, the mobile terminal and the base station may exchange thehigh-frequency frequency information of the two parties using the lowfrequency channel. In this way, complexity of high frequency beamalignment can be reduced, and high frequency beam alignment of a highfrequency antenna can be further quickly implemented.

Step 605: The base station and the mobile terminal exchange GPSinformation.

The base station and the mobile terminal start to establish highfrequency link synchronization. In order to narrow a search range,shorten a high frequency beam alignment time of a high frequencyantenna, and quickly complete high frequency link synchronization, thebase station and the mobile terminal may exchange the GPS informationbefore establishing high frequency link synchronization. For example,the mobile terminal may determine location information of the mobileterminal using a GPS, and send the location information to the basestation. Likewise, the base station may also determine locationinformation of the base station using the GPS, and send the locationinformation to the mobile terminal.

Step 606: The base station and the mobile terminal establish highfrequency link synchronization.

The base station and the mobile terminal exchange related information ofhigh frequency beam alignment using the low frequency channel in orderto determine a high frequency beam direction for high frequency antennaalignment in order to establish high frequency link synchronization.

Step 607: Complete high-low frequency link synchronization.

The base station and the mobile terminal perform step 607 afterestablishing high frequency link synchronization, that is, the basestation and the mobile terminal complete high-low frequency linksynchronization, and may transmit high-low frequency data.

FIG. 7 is a schematic flowchart of a process of aligning antenna beamsin a high-low frequency co-site network according to another embodimentof the present disclosure. The following describes the process in step606 in which the base station and the mobile terminal establish highfrequency link synchronization.

Step 701: Exchange coarse scanning information using a low frequencychannel.

A base station may agree on a scanning start time using the lowfrequency channel. The base station may further send or receive firstscanning information using the low frequency channel in order to performcoarse scanning. The first scanning information is used to indicate ascanning sector division manner or a quantity of scanning sectors of thebase station and a scanning sector division manner or a quantity ofscanning sectors of a mobile device. For example, the quantity ofscanning sectors of the mobile terminal is N, and the quantity ofscanning sectors of the base station is Q, N is a positive integer, andQ is a positive integer. The Q scanning sectors of the base station areseparately denoted as B₁, B₂, B₃, . . . , and B_(Q), and the N scanningsectors of the mobile terminal are separately denoted as U₁, U₂, U₃, . .. , and U_(N).

Step 702: Perform coarse scanning on a base station antenna and a mobileterminal antenna.

The base station first sends a high-frequency narrow beam of the regionB₁ to the mobile terminal in the region B₁ according to the firstscanning information, and the sending step lasts for a period of timeT₁. The mobile terminal successively receives, within T₁, thehigh-frequency narrow beam of the region B₁ regions U₁, U₂, U₃, . . . ,and U_(N). Afterwards, the base station sends a high-frequency narrowbeam of the region B₂ to the mobile terminal in the region B₂, and themobile terminal separately and successively receives, within T₁, thehigh-frequency narrow beam of the region B₂ in the regions U₁, U₂, U₃ .. . , and U_(N). In such a sequence, the base station successively sendshigh-frequency narrow beams to the mobile terminal in total Q regionsB₁, B₂, B₃, . . . , and B_(Q). The mobile terminal receives, using Q×Nhigh-frequency narrow beams in total, the Q high-frequency narrow beamssent by the base station, determines Q×N receiving statistics ofreceived signals on the Q×N high-frequency narrow beams that are in aone-to-one correspondence with the Q scanning sectors and the N scanningsectors 1, and records the Q×N receiving statistics in a Q×N matrix.

Step 703: The mobile terminal sends a coarse scanning result to the basestation using the low frequency channel.

The mobile terminal sends a first serial number q of the first scanningsector and a second serial number n of the second scanning sector to thebase station, where the first serial number q and the second serialnumber n correspond to a maximum receiving statistic in the Q×Nreceiving statistics. The base station and the mobile terminal mayperform step 707 after the coarse scanning, that is, point a transmitbeam and a receive beam to a direction of the maximum receivingstatistic according to q and n in order to perform high frequency beamalignment of a high frequency antenna. The base station and the mobileterminal may perform step 704 after the coarse scanning, that is,exchange fine scanning information, and continue to narrow a scanningrange.

Step 704: Exchange fine scanning information using the low frequencychannel.

The base station and the mobile terminal exchange, using the lowfrequency channel, information indicating that fine scanning continuesto be performed, and agree on second scanning information, for example,agree on a scanning sub-sector division manner or a quantity of scanningsub-sectors of a scanning sector corresponding to the first serialnumber and a scanning sub-sector division manner or a quantity ofscanning sub-sectors of a scanning sector corresponding to the secondserial number. It is assumed that the quantity of scanning sub-sectorsof the scanning sector corresponding to the first serial number is H,and the quantity of scanning sub-sectors of the scanning sectorcorresponding to the second serial number is P. The H scanningsub-sectors are separately denoted as B_(q1), B_(q2), B_(q3), . . . ,and B_(qH), and the P scanning sub-sectors are separately denoted asU_(n1), U_(n2), U_(n3), . . . , and U_(nP).

Step 705: Perform fine scanning on the base station antenna and themobile terminal antenna.

The base station first sends a high-frequency narrow beam of the regionB_(q1) to the mobile terminal in the region B_(q1) according to thesecond scanning information, and the sending step lasts for T₂. Themobile terminal separately receives, within T₂ in the regions U_(n1),U_(n2), U_(n3), . . . , and U_(nP) using P high-frequency narrow beams,the high-frequency narrow beam sent by the base station in the regionB_(q1). Afterwards, the base station sends a high-frequency narrow beamof the region B_(q2) to the mobile terminal in the region B_(q2). Themobile terminal separately receives, within T₂ in the regions U_(n1),U_(n2), U_(n3), . . . , and U_(nP) using P high-frequency narrow beams,the high-frequency narrow beam sent by the base station in the regionB_(q2). In such a sequence, the base station finally sends ahigh-frequency narrow beam of the region B_(qH) to the mobile terminalin the region B_(qH). The mobile terminal separately receives, within T₂in the regions U_(n1), U_(n2), U_(n3), . . . , and U_(nP) using Phigh-frequency narrow beams, the high-frequency narrow beam sent by thebase station in the region B_(qH). The mobile terminal receives, usingH×P high-frequency narrow beams in total, H high-frequency narrow beamssent by the base station in the H scanning sectors. After receiving thehigh-frequency narrow beams sent by the base station, the mobileterminal determines H×P receiving statistics of received signals on theH×P high-frequency narrow beams that are in a one-to-one correspondencewith a third scanning sector and a fourth scanning sector, and recordsthe H×P receiving statistics in an H×P matrix.

Step 706: The mobile terminal sends a fine scanning result to the basestation using the low frequency channel.

The mobile terminal sends a third serial number of the third scanningsector and a fourth serial number of the fourth scanning sector to thebase station, where the third serial number and the fourth serial numbercorrespond to a maximum receiving statistic in the H×P receivingstatistics.

Step 707: The base station and the mobile terminal target a beam at adirection of a maximum receiving statistic.

The base station and the mobile terminal point the transmit beam and thereceive beam to the direction of the maximum receiving statisticaccording to the third serial number and the fourth serial number inorder to perform high frequency beam alignment of a high frequencyantenna.

Step 708: Determine whether to establish high frequency linksynchronization.

Step 709: Complete high-low frequency link synchronization.

After step 707, the base station and the mobile terminal determinewhether to establish high frequency link synchronization. If highfrequency link synchronization is not established, return to step 701,that is, the base station and the mobile terminal re-exchange coarsescanning information to perform coarse scanning. If high frequency linksynchronization is established, step 709 is performed, that is, the basestation and the mobile terminal complete high-low frequency linksynchronization, and may transmit high-low frequency data.

FIG. 8 is a signaling flowchart of aligning antenna beams in a high-lowfrequency co-site network according to an embodiment of the presentdisclosure. In FIG. 8, a solid line indicates that a low frequency beamis used for communication, and a dashed line indicates that a highfrequency beam is used for communication.

Step 801: Establish a low frequency channel.

A base station and a mobile terminal complete low frequency linksynchronization to establish the low frequency channel, and may transmitlow frequency data. Step 801 may correspond to step 401 to step 403 inthe embodiment in FIG. 4.

Step 802: Send and receive a high-frequency narrow beam.

The base station estimates a DOA using the low frequency channel, andsends a high-frequency narrow beam to the mobile terminal in a DOAestimation range. The mobile terminal receives the high-frequency narrowbeam, and parses an ID of the high-frequency narrow beam. Step 802 maycorrespond to step 501 and step 502 in the embodiment in FIG. 5.

Step 803: Feedback an ID of a beam with maximum power using the lowfrequency channel.

The mobile terminal sends, to the base station using the low frequencychannel, a first ID corresponding to a high-frequency narrow beam withmaximum power. Step 803 may correspond to step 503 to step 505 in theembodiment in FIG. 5.

Step 804: Send a high-frequency narrow beam corresponding to an ID withmaximum power.

The base station sends the high-frequency narrow beam with maximum powerto the mobile terminal according to the received ID corresponding to thehigh-frequency narrow beam with maximum power. The mobile terminalreceives the high-frequency narrow beam, and parses an ID in order toobtain a second ID corresponding to the high-frequency narrow beam withmaximum power. Step 804 may correspond to step 506 in the embodiment inFIG. 5.

Step 805: Complete high frequency link synchronization, and transmithigh frequency data.

The base station and the mobile terminal implement high frequency beamalignment of a high frequency antenna, complete high frequency linksynchronization, and may transmit high frequency data. Step 805 maycorrespond to step 507 to step 508 in the embodiment in FIG. 5.

FIG. 9 is a signaling flowchart of aligning antenna beams in a high-lowfrequency co-site network according to another embodiment of the presentdisclosure. In FIG. 9, a solid line indicates that a low frequency beamis used for communication, and a dashed line indicates that a highfrequency beam is used for communication.

Step 901: Establish a low frequency channel.

A base station and a mobile terminal complete low frequency linksynchronization to establish the low frequency channel, and may transmitlow frequency data. Step 901 may correspond to step 601 and step 602 inthe embodiment in FIG. 6.

Step 902: Exchange scanning information using the low frequency channel.

The base station and the mobile terminal may exchange scanninginformation using the low frequency channel, to perform scanning. Thescanning information herein includes coarse scanning information andfine scanning information. Step 907 may correspond to step 701 and step704 in the embodiment in FIG. 7.

Step 903: Return a scanning result using the low frequency channel.

The base station and the mobile terminal may return the scanning resultusing the low frequency channel, obtain a beam direction required by thebase station and the mobile terminal to perform high frequency beamalignment of a high frequency antenna, and target a beam at a directionof maximum power. Step 903 may correspond to step 703 and step 706 inthe embodiment in FIG. 7.

Step 904: Complete high frequency link synchronization to establish ahigh frequency data connection.

The base station and the mobile terminal implement high frequency beamalignment of a high frequency antenna, complete high frequency linksynchronization, and may transmit high frequency data. Step 904 maycorrespond to step 707 to step 709 in the embodiment in FIG. 7.

A method, a process, and signaling interaction for aligning antennabeams in a high-low frequency co-site network according to embodimentsof the present disclosure are described above in detail with referenceto FIG. 2 to FIG. 9 respectively from perspectives of a base station, amobile terminal, and interaction between the two. The followingdescribes a base station and a mobile terminal for aligning antennabeams in a high-low frequency co-site network according to theembodiments of the present disclosure with reference to FIG. 10 to FIG.13 respectively from perspectives of a base station and a mobileterminal.

FIG. 10 is a block diagram of a base station for aligning antenna beamsin a high-low frequency co-site network according to an embodiment ofthe present disclosure. The base station 10 in FIG. 10 is, for example,similar to the base station 101 in FIG. 1, and includes an establishmentunit 11, an obtaining unit 12, a determining unit 13, and an alignmentunit 14.

The establishment unit 11 is configured to establish a low frequencychannel with a low frequency antenna of a communications device.

The obtaining unit 12 is configured to obtain location information ofthe communications device using the low frequency channel established bythe establishment unit 11.

The determining unit 13 is configured to determine a scanning range of ahigh frequency beam according to the location information of thecommunications device that is obtained by the obtaining unit 12.

The alignment unit 14 is configured to perform high frequency beamalignment of a high frequency antenna with the communications deviceaccording to the scanning range that is of the high frequency beam andis determined by the determining unit 13.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time of a high frequency antenna is long due toa narrow field of view of a high frequency beam can be avoided such thathigh frequency beam alignment of a high frequency antenna can be quicklyimplemented.

The base station 10 in this embodiment of the present disclosure mayimplement operations or functions related to the base station in theembodiments in FIG. 2, and FIG. 4 to FIG. 9. In order to avoidrepetition, details are not described herein again.

Optionally, in another embodiment, the obtaining unit 12 is furtherconfigured to receive, using the low frequency channel, the locationinformation of the communications device that is determined using a GPSand is sent by the communications device.

Optionally, in another embodiment, the obtaining unit 12 is furtherconfigured to estimate a DOA of a low frequency beam using the lowfrequency channel, to obtain DOA information of the low frequency beam,and determine the location information of the communications deviceaccording to the DOA information of the low frequency beam.

Optionally, in another embodiment, the alignment unit 14 is furtherconfigured to send M high-frequency narrow beams to the communicationsdevice according to the scanning range of the high frequency beam, whereeach high-frequency narrow beam carries ID information used to indicatean ID of each high-frequency narrow beam, receive a first ID, of a firsthigh-frequency narrow beam, that corresponds to a first maximumreceiving statistic and is sent by the communications device, where thefirst maximum receiving statistic is a maximum value in M receivingstatistics of received signals on the M high-frequency narrow beamsreceived by the communications device, and the first high-frequencynarrow beam is one of the M high-frequency narrow beams, send the firsthigh-frequency narrow beam to the communications device, and performhigh frequency beam alignment of a high frequency antenna with thecommunications device according to the first ID.

Optionally, in another embodiment, the base station 10 is an accessdevice of the communications device, and the alignment unit 14 isfurther configured to send, using the low frequency channel, firstscanning information to the communications device, or receive firstscanning information sent by the communications device, where the firstscanning information is used to indicate a scanning sector divisionmanner or a quantity of scanning sectors of the communications deviceand a scanning sector division manner or a quantity of scanning sectorsof the access device, and perform high frequency beam alignment of ahigh frequency antenna according to the first scanning information.

Optionally, in another embodiment, the alignment unit 14 sends ahigh-frequency narrow beam to the communications device in a firstscanning sector such that the communications device receives thehigh-frequency narrow beam in a second scanning sector, where the firstscanning sector is any one of Q scanning sectors, and the secondscanning sector is any one of N scanning sectors, receives a firstserial number of the first scanning sector and a second serial number ofthe second scanning sector, where the first serial number and the secondserial number correspond to a second maximum receiving statistic and aresent by the communications device, and the second maximum receivingstatistic is a maximum value in Q×N receiving statistics of receivedsignals on Q×N high-frequency narrow beams determined by thecommunications device, and performs high frequency beam alignment of ahigh frequency antenna with the communications device according to thefirst serial number and the second serial number, where the quantity ofscanning sectors of the communications device is N, the quantity ofscanning sectors of the access device is Q, N is a positive integer, andQ is a positive integer.

Optionally, in another embodiment, the alignment unit 14 is furtherconfigured to using the low frequency channel, send second scanninginformation to the communications device, or receive second scanninginformation sent by the communications device, where the second scanninginformation is used to indicate a scanning sub-sector division manner ora quantity of scanning sub-sectors of a scanning sector corresponding tothe first serial number and a scanning sub-sector division manner or aquantity of scanning sub-sectors of a scanning sector corresponding tothe second serial number, the quantity of scanning sub-sectors of thescanning sector corresponding to the first serial number is H, thequantity of scanning sub-sectors of the scanning sector corresponding tothe second serial number is P, H is a positive integer, and P is apositive integer, send a high-frequency narrow beam to thecommunications device in a scanning sub-sector of the scanning sectorcorresponding to the first serial number such that the communicationsdevice receives the high-frequency narrow beam in a scanning sub-sectorof the scanning sector corresponding to the second serial number, wherethe third scanning sector is any one of the H scanning sub-sectors, andthe fourth scanning sector is any one of the P scanning sub-sectors,receive a third serial number of the third scanning sector and a fourthserial number of the fourth scanning sector, where the third serialnumber and the fourth serial number correspond to a third maximumreceiving statistic and are sent by the communications device, and thethird maximum receiving statistic is a maximum value in H×P receivingstatistics of received signals on H×P high-frequency narrow beamsreceived by the communications device, and perform high frequency beamalignment of a high frequency antenna with the communications deviceaccording to the third serial number and the fourth serial number.

Optionally, in another embodiment, the receiving statistic includes atleast one of the following parameters power, an SNR, or an RSL.

Optionally, in another embodiment, the base station 10 is furtherconfigured to perform mutual authentication with the communicationsdevice using the low frequency channel, or send high-frequency frequencyinformation to the communications device.

Optionally, in another embodiment, the alignment unit 14 is furtherconfigured to send, using the low frequency channel, a scanning starttime to the communications device, or receive a scanning start time sentby the communications device, and start, at the scanning start time, toperform high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range of the highfrequency beam.

FIG. 11 is a block diagram of a mobile terminal 20 for aligning antennabeams in a high-low frequency co-site network according to anotherembodiment of the present disclosure. The mobile terminal 20 in FIG. 11is, for example, the mobile terminal 103 in FIG. 1, and includes anestablishment unit 21, an obtaining unit 22, a determining unit 23, andan alignment unit 24.

The establishment unit 21 is configured to establish a low frequencychannel with a low frequency antenna of a communications device.

The obtaining unit 22 is configured to obtain location information ofthe communications device using the low frequency channel established bythe establishment unit 21.

The determining unit 23 is configured to determine a scanning range of ahigh frequency beam according to the location information of thecommunications device that is obtained by the obtaining unit 22.

The alignment unit 24 is configured to perform high frequency beamalignment of a high frequency antenna with the communications deviceaccording to the scanning range that is of the high frequency beam andis determined by the determining unit 23.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time of a high frequency antenna is long due toa narrow field of view of a high frequency beam can be avoided such thathigh frequency beam alignment of a high frequency antenna can be quicklyimplemented.

The mobile terminal 20 in this embodiment of the present disclosure mayimplement operations or functions related to the mobile terminal in theembodiments in FIG. 3 to FIG. 9. In order to avoid repetition, detailsare not described herein again.

Optionally, in another embodiment, the obtaining unit 22 is furtherconfigured to receive, using the low frequency channel, the locationinformation of the communications device that is determined using a GPSand is sent by the communications device.

Optionally, in another embodiment, the alignment unit 24 is furtherconfigured to receive, in the scanning range of the high frequency beam,M high-frequency narrow beams sent by the communications device, whereeach high-frequency narrow beam carries ID information used to indicatean ID of each high-frequency narrow beam, determine M receivingstatistics that are of received signals on the high-frequency narrowbeams and correspond to the M high-frequency narrow beams, send, to thecommunications device, a first ID that is of a first high-frequencynarrow beam and corresponds to a first maximum receiving statistic,where the first maximum receiving statistic is a maximum value in the Mreceiving statistics of received signals on the received Mhigh-frequency narrow beams, and the first high-frequency narrow beam isone of the M high-frequency narrow beams, receive, using Ghigh-frequency narrow beams, the first high-frequency narrow beam sentby the communications device, determine a second ID corresponding to ahigh-frequency narrow beam with a maximum receiving statistic in the Ghigh-frequency narrow beams, and perform high frequency beam alignmentof a high frequency antenna with the communications device according tothe first ID and the second ID.

Optionally, in another embodiment, the mobile terminal 20 is an accessdevice of the communications device, and the alignment unit 24 isfurther configured to send, using the low frequency channel, firstscanning information to the communications device, or receive firstscanning information sent by the communications device, where the firstscanning information is used to indicate a scanning sector divisionmanner or a quantity of scanning sectors of the communications deviceand a scanning sector division manner or a quantity of scanning sectorsof the access device, and perform high frequency beam alignment of ahigh frequency antenna according to the scanning range of the highfrequency beam and the first scanning information.

Optionally, in another embodiment, the alignment unit 24 is furtherconfigured to receive, by the access device in a second scanning sector,a high-frequency narrow beam sent by the communications device in afirst scanning sector, where the first scanning sector is any one of Qscanning sectors, and the second scanning sector is any one of Nscanning sectors, determine receiving statistics of received signals onQ×N high-frequency narrow beams that are in a one-to-one correspondencewith the Q scanning sectors and the N scanning sectors, to obtain Q×Nreceiving statistics, send a first serial number of the first scanningsector and a second serial number of the second scanning sector to thecommunications device, where the first serial number and the secondserial number correspond to a second maximum receiving statistic, andthe second maximum receiving statistic is a maximum value in the Q×Nreceiving statistics of received signals on the Q×N high-frequencynarrow beams, and perform high frequency beam alignment of a highfrequency antenna with the communications device according to the firstserial number and the second serial number, where the quantity ofscanning sectors of the communications device is Q, the quantity ofscanning sectors of the access device is N, Q is a positive integer, andN is a positive integer.

Optionally, in another embodiment, the alignment unit 24 is furtherconfigured to send, using the low frequency channel, second scanninginformation to the communications device, or receive second scanninginformation sent by the communications device, where the second scanninginformation is used to indicate a scanning sub-sector division manner ora quantity of scanning sub-sectors of a scanning sector corresponding tothe first serial number and a scanning sub-sector division manner or aquantity of scanning sub-sectors of a scanning sector corresponding tothe second serial number, the quantity of scanning sub-sectors of thescanning sector corresponding to the first serial number is H, thequantity of scanning sub-sectors of the scanning sector corresponding tothe second serial number is P, H is a positive integer, and P is apositive integer, determine receiving statistics of received signals onH×P high-frequency narrow beams that are in a one-to-one correspondencewith the H scanning sectors and the P scanning sectors, to obtain H×Preceiving statistics, send a third serial number of a third scanningsector and a fourth serial number of the fourth scanning sector to thecommunications device, where the third serial number and the fourthserial number correspond to a third maximum receiving statistic, and thethird maximum receiving statistic is a maximum value in the H×Preceiving statistics of received signals on H×P high-frequency narrowbeams, and perform high frequency beam alignment of a high frequencyantenna with the communications device according to the third serialnumber and the fourth serial number.

Optionally, in another embodiment, the receiving statistic includes atleast one of the following parameters power, an SNR, or an RSL.

Optionally, in another embodiment, the mobile terminal 20 is furtherconfigured to perform mutual authentication with the communicationsdevice using the low frequency channel, or send high-frequency frequencyinformation to the communications device using the low frequencychannel.

Optionally, in another embodiment, the alignment unit 24 is furtherconfigured to send, using the low frequency channel, a scanning starttime to the communications device, or receive a scanning start time sentby the communications device, and start, at the scanning start time inorder to perform high frequency beam alignment of a high frequencyantenna with the communications device according to the scanning rangeof the high frequency beam.

FIG. 12 is a block diagram of a base station 30 for aligning antennabeams in a high-low frequency co-site network according to anotherembodiment of the present disclosure.

The base station 30 in FIG. 12 may be configured to implement steps andmethods in the foregoing method embodiments. In the embodiment in FIG.12, the base station 30 includes a high frequency antenna 31, a lowfrequency antenna 32, a transmitter 33, a receiver 34, a processor 35,and a memory 36. The processor 35 controls an operation of the basestation 30, and may be configured to process a signal. The memory 36 mayinclude a read-only memory (ROM) and a random access memory (RAM), andprovide an instruction and data for the processor 35. A part of thememory 36 may further include a nonvolatile RAM (NVRAM). The transmitter33 and the receiver 34 may be coupled to the high frequency antenna 31and the low frequency antenna 32. Components of the base station 30 arecoupled together using a bus system 37. In addition to a data bus, thebus system 37 further includes a power bus, a control bus, and a statussignal bus. However, for clarity of description, various buses aremarked as the bus system 37 in FIG. 12.

The methods disclosed in the foregoing embodiments of the presentdisclosure may be applied to the processor 35, or be implemented by theprocessor 35. In an implementation process, steps in the foregoingmethods may be completed using an integrated logic circuit of hardwarein the processor 35 or an instruction in a software form. The processor35 may be a general purpose processor, a digital signal processor, anapplication-specific integrated circuit, a field programmable gate arrayor another programmable logic device, a discrete gate or a transistorlogic device, or a discrete hardware component, and may implement orexecute methods, steps, and logic block diagrams that are disclosed inthe embodiments of the present disclosure. The general purpose processormay be a microprocessor, any conventional processor, or the like. Stepsof the methods disclosed with reference to the embodiments of thepresent disclosure may be directly executed and completely using ahardware processor, or may be executed and completely using acombination of hardware and software modules in the processor 35. Thesoftware module may be located in a mature storage medium in the art,such as a RAM, a flash memory, a ROM, a programmable read-only memory(PROM), an electrically erasable programmable memory, or a register. Thestorage medium is located in the memory 36. The processor 35 readsinformation in the memory 36, and completes the steps of the foregoingmethods with reference to the hardware of the processor 35.

The processor 35 may be configured to establish a low frequency channelwith a low frequency antenna of a communications device, and obtainlocation information of the communications device using the lowfrequency channel. The processor 35 is further configured to determine ascanning range of a high frequency beam according to the locationinformation of the communications device, and perform high frequencybeam alignment of a high frequency antenna with the communicationsdevice according to the scanning range of the high frequency beam.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time is long due to a narrow field of view of ahigh frequency beam can be avoided such that high frequency beamalignment of a high frequency antenna can be quickly implemented.

In specific application, the communications device may be built in ormay be a wireless communications device such as a mobile phone, and mayfurther include a carrier that accommodates a transmit circuit and areceive circuit in order to allow data transmission and receivingbetween the communications device and a remote location. The transmitcircuit and the receive circuit may be coupled to an antenna. Componentsof the communications device are coupled together using a bus (alsoreferred to as a bus system). The communications device may furtherinclude a processing unit for signal processing, and further includes apower controller and a decoding processor. Further, decoders indifferent products may be integrated with the processing unit.

The base station 30 can implement operations related to the base stationin the foregoing method embodiments. In order to avoid repetition,details are not described herein again.

Optionally, in an embodiment, the receiver 34 may receive, using the lowfrequency channel, the location information of the communications devicethat is determined using a GPS and is sent by the communications device.

Optionally, in another embodiment, the processor 35 may estimate a DOAof a low frequency beam using the low frequency channel, to obtain DOAinformation of the low frequency beam, and determine the locationinformation of the communications device according to the DOAinformation of the low frequency beam.

Optionally, in another embodiment, the transmitter 33 may send Mhigh-frequency narrow beams to the communications device according tothe scanning range of the high frequency beam, where each high-frequencynarrow beam carries ID information used to indicate an ID of eachhigh-frequency narrow beam. The receiver 34 may receive a first ID, of afirst high-frequency narrow beam, that corresponds to a first maximumreceiving statistic and is sent by the communications device, where thefirst maximum receiving statistic is a maximum value in M receivingstatistics of received signals on the M high-frequency narrow beamsreceived by the communications device, and the first high-frequencynarrow beam is one of the M high-frequency narrow beams. The transmitter33 may send the first high-frequency narrow beam to the communicationsdevice. The processor 35 may perform high frequency beam alignment of ahigh frequency antenna with the communications device according to thefirst ID.

Optionally, in another embodiment, the base station 30 is an accessdevice of the communications device. The transmitter 33 sends firstscanning information to the communications device using the lowfrequency channel, or the receiver 34 receives, using the low frequencychannel, first scanning information sent by the communications device,where the first scanning information is used to indicate a scanningsector division manner or a quantity of scanning sectors of thecommunications device and a scanning sector division manner or aquantity of scanning sectors of the access device. The processor 35performs high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range of the highfrequency beam and the first scanning information.

Optionally, in another embodiment, the transmitter 33 sends ahigh-frequency narrow beam to the communications device in a firstscanning sector such that the communications device receives thehigh-frequency narrow beam in a second scanning sector, where the firstscanning sector is any one of Q scanning sectors, and the secondscanning sector is any one of N scanning sectors. The receiver 34receives a first serial number of the first scanning sector and a secondserial number of the second scanning sector, where the first serialnumber and the second serial number correspond to a second maximumreceiving statistic and are sent by the communications device, and thesecond maximum receiving statistic is a maximum value in Q×N receivingstatistics of received signals on Q×N high-frequency narrow beamsdetermined by the communications device. The processor 35 performs highfrequency beam alignment of a high frequency antenna with thecommunications device according to the first serial number and thesecond serial number, where the quantity of scanning sectors of thecommunications device is N, the quantity of scanning sectors of theaccess device is Q, N is a positive integer, and Q is a positiveinteger.

Optionally, in another embodiment, the transmitter 33 sends secondscanning information to the communications device using the lowfrequency channel, or the receiver 34 receives second scanninginformation sent by the communications device, where the second scanninginformation is used to indicate a scanning sub-sector division manner ora quantity of scanning sub-sectors of a scanning sector corresponding tothe first serial number and a scanning sub-sector division manner or aquantity of scanning sub-sectors of a scanning sector corresponding tothe second serial number, the quantity of scanning sub-sectors of thescanning sector corresponding to the first serial number is H, thequantity of scanning sub-sectors of the scanning sector corresponding tothe second serial number is P, H is a positive integer, and P is apositive integer. The transmitter 33 sends a high-frequency narrow beamto the communications device in a scanning sub-sector of the scanningsector corresponding to the first serial number such that thecommunications device receives the high-frequency narrow beam in ascanning sub-sector of the scanning sector corresponding to the secondserial number, where the third scanning sector is any one of the Hscanning sub-sectors, and the fourth scanning sector is any one of the Pscanning sub-sectors. The receiver 34 receives a third serial number ofthe third scanning sector and a fourth serial number of the fourthscanning sector, where the third serial number and the fourth serialnumber correspond to a third maximum receiving statistic and are sent bythe communications device, and the third maximum receiving statistic isa maximum value in H×P receiving statistics of received signals on H×Phigh-frequency narrow beams received by the communications device. Theprocessor 35 performs high frequency beam alignment of a high frequencyantenna with the communications device according to the third serialnumber and the fourth serial number.

Optionally, in another embodiment, the receiving statistic includes atleast one of the following parameters power, an SNR, or an RSL.

Optionally, in another embodiment, the processor 35 may further performmutual authentication with the communications device using the lowfrequency channel, or the transmitter 33 may send high-frequencyfrequency information to the communications device using the lowfrequency channel.

Optionally, in another embodiment, the transmitter 33 is furtherconfigured to send a scanning start time to the communications deviceusing the low frequency channel. The receiver 34 is further configuredto receive, using the low frequency channel, a scanning start time sentby the communications device. The processor 35 is configured to start,at the scanning start time in order to perform high frequency beamalignment of a high frequency antenna with the communications deviceaccording to the scanning range of the high frequency beam.

FIG. 13 is a block diagram of a mobile terminal for aligning antennabeams in a high-low frequency co-site network according to anotherembodiment of the present disclosure.

A mobile terminal 40 in FIG. 13 may be configured to implement steps andmethods in the foregoing method embodiments. In the embodiment in FIG.13, the mobile terminal 40 includes a high frequency antenna 41, a lowfrequency antenna 42, a transmitter 43, a receiver 44, a processor 45,and a memory 46. The processor 45 controls an operation of the mobileterminal 40, and may be configured to process a signal. The memory 46may include a ROM and a RAM, and provide an instruction and data for theprocessor 45. The transmitter 43 and the receiver 44 may be coupled tothe high frequency antenna 41 and the low frequency antenna 42.Components of the mobile terminal 40 are coupled together using a bussystem 47. In addition to a data bus, the bus system 47 further includesa power bus, a control bus, and a status signal bus. However, forclarity of description, various buses are marked as the bus system 47 inFIG. 13. The processor 45 is configured to establish a low frequencychannel with a low frequency antenna of a communications device, andperform high frequency beam alignment of a high frequency antenna withthe communications device using the low frequency channel.

The methods disclosed in the foregoing embodiments of the presentdisclosure may be applied to the processor 45, or be implemented by theprocessor 45. In an implementation process, steps in the foregoingmethods may be completed using an integrated logic circuit of hardwarein the processor 45 or an instruction in a software form. The processor45 may be a general-purpose processor, a digital signal processor, anapplication-specific integrated circuit, a field programmable gate arrayor another programmable logic device, a discrete gate or a transistorlogic device, or a discrete hardware component, and may implement orexecute methods, steps, and logic block diagrams that are disclosed inthe embodiments of the present disclosure. The general purpose processormay be a microprocessor, any conventional processor, or the like. Stepsof the methods disclosed with reference to the embodiments of thepresent disclosure may be directly executed and completely using ahardware processor, or may be executed and completely using acombination of hardware and software modules in the processor 45. Thesoftware module may be located in a mature storage medium in the art,such as a RAM, a flash memory, a ROM, a PROM, an electrically erasableprogrammable memory, or a register. The storage medium is located in thememory 46. The processor 45 reads information in the memory 46, andcompletes the steps of the foregoing methods with reference to thehardware of the processor 45.

Further, the processor 45 may be configured to establish a low frequencychannel with a low frequency antenna of a communications device, andobtain location information of the communications device using the lowfrequency channel. The processor 45 is further configured to determine ascanning range of a high frequency beam according to the locationinformation of the communications device, and perform high frequencybeam alignment of a high frequency antenna with the communicationsdevice according to the scanning range of the high frequency beam.

In this embodiment of the present disclosure, when performing antennabeam alignment in a high-low frequency co-site network, a base stationand a mobile terminal first establish a low frequency channel, and thenperform high frequency beam alignment of a high frequency antenna usingthe low frequency channel. In this way, a technical problem that a highfrequency beam alignment time is long due to a narrow field of view of ahigh frequency beam can be avoided such that high frequency beamalignment of a high frequency antenna can be quickly implemented.

The mobile terminal 40 can implement operations related to the mobileterminal in the foregoing method embodiments. To avoid repetition,details are not described herein again.

Optionally, in an embodiment, the receiver 44 is configured to receive,using the low frequency channel, the location information of thecommunications device that is determined using a GPS and is sent by thecommunications device.

Optionally, in another embodiment, the receiver 44 may receive, in thescanning range of the high frequency beam, M high-frequency narrow beamssent by the communications device, where each high-frequency narrow beamcarries ID information used to indicate an ID of each high-frequencynarrow beam. The processor 45 may determine M receiving statistics ofthe M high-frequency narrow beams. The transmitter 43 sends, to thecommunications device, a first ID that is of a first high-frequencynarrow beam and corresponds to a first maximum receiving statistic,where the first maximum receiving statistic is a maximum value in the Mreceiving statistics corresponding to the received M high-frequencynarrow beams, and the first high-frequency narrow beam is one of the Mhigh-frequency narrow beams. The receiver 44 receives, using Ghigh-frequency narrow beams, the first high-frequency narrow beam sentby the communications device. The processor 45 determines a second IDcorresponding to a high-frequency narrow beam with a maximum receivingstatistic in the G high-frequency narrow beams, and performs highfrequency beam alignment of a high frequency antenna with thecommunications device according to the first ID and the second ID.

Optionally, in another embodiment, the mobile terminal 40 is an accessdevice of the communications device. The transmitter 43 sends firstscanning information to the communications device using the lowfrequency channel, or the receiver 44 receives, using the low frequencychannel, first scanning information sent by the communications device,where the first scanning information is used to indicate a scanningsector division manner or a quantity of scanning sectors of thecommunications device and a scanning sector division manner or aquantity of scanning sectors of the access device. The processor 45performs high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range of the highfrequency beam and the first scanning information.

Optionally, in another embodiment, the receiver 44 receives, in a secondscanning sector, a high-frequency narrow beam sent by the communicationsdevice in a first scanning sector, where the first scanning sector isany one of Q scanning sectors, and the second scanning sector is any oneof N scanning sectors. The processor 45 determines receiving statisticsof received signals on Q×N high-frequency narrow beams that are in aone-to-one correspondence with the Q scanning sectors and the N scanningsectors, to obtain Q×N receiving statistics. The transmitter 43 sends afirst serial number of the first scanning sector and a second serialnumber of the second scanning sector to the communications device, wherethe first serial number and the second serial number correspond to asecond maximum receiving statistic, and the second maximum receivingstatistic is a maximum value in the Q×N receiving statistics. Theprocessor 45 performs high frequency beam alignment of a high frequencyantenna with the communications device according to the first serialnumber and the second serial number, where the quantity of scanningsectors of the communications device is Q, the quantity of scanningsectors of the access device is N, Q is a positive integer, and N is apositive integer.

Optionally, in another embodiment, the transmitter 43 sends secondscanning information to the communications device using the lowfrequency channel, or the receiver 44 receives, using the low frequencychannel, second scanning information sent by the communications device,where the second scanning information is used to indicate a scanningsub-sector division manner or a quantity of scanning sub-sectors of ascanning sector corresponding to the first serial number and a scanningsub-sector division manner or a quantity of scanning sub-sectors of ascanning sector corresponding to the second serial number, the quantityof scanning sub-sectors of the scanning sector corresponding to thefirst serial number is H, the quantity of scanning sub-sectors of thescanning sector corresponding to the second serial number is P, H is apositive integer, and P is a positive integer. The processor 45determines receiving statistics of received signals on H×Phigh-frequency narrow beams that are in a one-to-one correspondence withthe H scanning sectors and the P scanning sectors, to obtain H×Preceiving statistics. The transmitter 43 sends a third serial number ofa third scanning sector and a fourth serial number of the fourthscanning sector to the communications device, where the third serialnumber and the fourth serial number correspond to a third maximumreceiving statistic, and the third maximum receiving statistic is amaximum value in the H×P receiving statistics. The processor 45 performshigh frequency beam alignment of a high frequency antenna with thecommunications device according to the third serial number and thefourth serial number.

Optionally, in another embodiment, the processor 45 may be furtherconfigured to perform mutual authentication with the communicationsdevice using the low frequency channel, or the transmitter 43 sendshigh-frequency frequency information to the communications device usingthe low frequency channel.

Optionally, in another embodiment, the transmitter 43 is furtherconfigured to send a scanning start time to the communications deviceusing the low frequency channel, or the receiver 44 receives a scanningstart time sent by the communications device. The processor 45 starts,at the scanning start time, to perform high frequency beam alignment ofa high frequency antenna with the communications device according to thescanning range of the high frequency beam.

It should be understood that in this embodiment of the presentdisclosure, the low frequency channel may further be a wired channelsuch as an optical network. This is not limited in the presentdisclosure.

Description is provided only using antenna beam alignment between a basestation and a mobile terminal as an example in the embodiments of thepresent disclosure. The present disclosure may be also applied to beamalignment between a base station and a base station antenna, or may beapplied to beam alignment between a mobile terminal and a mobileterminal antenna.

It should be understood that “an embodiment” or “an embodiment”mentioned in the whole specification does not mean that particularfeatures, structures, or characteristics related to the embodiment areincluded in at least one embodiment of the present disclosure.Therefore, “in an embodiment” appearing throughout the specificationdoes not refer to a same embodiment. In addition, these particularfeatures, structures, or characteristics may be combined in one or moreembodiments using any appropriate manner.

It should be understood that sequence numbers of the foregoing processesdo not mean execution sequences in various embodiments of the presentdisclosure. The execution sequences of the processes should bedetermined according to functions and internal logic of the processes,and should not be construed as any limitation on the implementationprocesses of the embodiments of the present disclosure.

It should be understood that in the embodiments of the presentdisclosure, “B corresponding to A” indicates that B is associated withA, and B may be determined according to A. However, it should further beunderstood that determining A according to B does not mean that B isdetermined according to A only, that is, B may also be determinedaccording to A and/or other information.

The term “and/or” in this specification describes only an associationrelationship for describing associated objects and represents that threerelationships may exist. For example, A and/or B may represent thefollowing three cases, only A exists, both A and B exist, and only Bexists. In addition, the character “/” in this specification generallyindicates an “or” relationship between the associated objects.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by hardware or softwaredepends on particular applications and design constraint conditions ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of the present disclosure.

In the several embodiments provided in the present application, itshould be understood that the disclosed system, apparatus, and methodmay be implemented in other manners. For example, the describedapparatus embodiment is merely an example. For example, the unitdivision is merely logical function division and may be other divisionin actual implementation. For example, a plurality of units orcomponents may be combined or integrated into another system, or somefeatures may be ignored or not performed. In addition, the displayed ordiscussed mutual couplings or direct couplings or communicationconnections may be implemented using some interfaces. The indirectcouplings or communication connections between the apparatuses or unitsmay be implemented in electronic, mechanical, or other forms.

The units described as separate parts may or may not be physicallyseparate, and parts displayed as units may or may not be physical units,may be located in one position, or may be distributed on a plurality ofnetwork units. Some or all of the units may be selected according toactual needs to achieve the objectives of the solutions of theembodiments.

In addition, functional units in the embodiments of the presentdisclosure may be integrated into one processing unit, or each of theunits may exist alone physically, or two or more units are integratedinto one unit.

The foregoing descriptions are merely specific implementations of thepresent disclosure, but are not intended to limit the protection scopeof the present disclosure. Any variation or replacement readily figuredout by a person skilled in the art within the technical scope disclosedin the present disclosure shall fall within the protection scope of thepresent disclosure. Therefore, the protection scope of the presentdisclosure shall be subject to the protection scope of the claims.

What is claimed is:
 1. A method for aligning antenna beams in a high-lowfrequency co-site network, comprising: establishing a low frequencychannel with a low frequency antenna of a communications device;obtaining location information of the communications device using thelow frequency channel; determining a scanning range of a high frequencybeam according to the location information of the communications device;and performing high frequency beam alignment of a high frequency antennawith the communications device according to the scanning range of thehigh frequency beam; wherein the method is executed by an access deviceof the communications device, and wherein performing the high frequencybeam alignment of the high frequency antenna with the communicationsdevice comprises: sending, using the low frequency channel, firstscanning information to the communications device, or receiving thefirst scanning information from the communications device, wherein thefirst scanning information indicates a scanning sector division manner,a quantity of scanning sectors of the communications device and thescanning sector division manner, or a quantity of scanning sectors ofthe access device; and performing the high frequency beam alignment ofthe high frequency antenna according to the scanning range of the highfrequency beam and the first scanning information; and wherein thequantity of scanning sectors of the communications device is Q, whereinthe quantity of scanning sectors of the access device is N, wherein Q isa positive integer, wherein N is a positive integer, and whereinperforming the high frequency beam alignment of the high frequencyantenna comprises: sending, by the access device, a high-frequencynarrow beam to the communications device in a first scanning sector suchthat the communications device receives the high-frequency narrow beamin a second scanning sector, wherein the first scanning sector is anyone of the Q scanning sectors, and wherein the second scanning sector isany one of the N scanning sectors; receiving a first serial number ofthe first scanning sector and a second serial number of the secondscanning sector, wherein the first serial number and the second serialnumber correspond to a first maximum receiving statistic from thecommunications device, and wherein the first maximum receiving statisticis a maximum value in Q×N receiving statistics of received signals onQ×N high-frequency narrow beams received by the communications device;and performing the high frequency beam alignment of the high frequencyantenna with the communications device according to the first serialnumber and the second serial number.
 2. The method according to claim 1,wherein obtaining the location information of the communications devicecomprises receiving, using the low frequency channel, the locationinformation of the communications device determined using a globalpositioning system (GPS) from the communications device.
 3. The methodaccording to claim 1, wherein obtaining the location information of thecommunications device comprises: estimating a direction of arrival (DOA)of a low frequency beam using the low frequency channel to obtain DOAinformation of the low frequency beam; and determining the locationinformation of the communications device according to the DOAinformation of the low frequency beam.
 4. The method according to claim1, wherein performing the high frequency beam alignment of the highfrequency antenna with the communications device comprises: sending Mhigh-frequency narrow beams to the communications device according tothe scanning range of the high frequency beam, wherein eachhigh-frequency narrow beam carries identity (ID) information indicatingan ID of each high-frequency narrow beam, and wherein M is a positiveinteger; receiving a first ID of a first high-frequency narrow beamcorresponding to a second maximum receiving statistic from thecommunications device, wherein the second maximum receiving statistic isa maximum value in M receiving statistics of received signals on the Mhigh-frequency narrow beams received by the communications device, andwherein the first high-frequency narrow beam is one of the Mhigh-frequency narrow beams; sending the first high-frequency narrowbeam to the communications device; and performing the high frequencybeam alignment of the high frequency antenna with the communicationsdevice according to the first ID.
 5. The method according to claim 1,wherein performing the high frequency beam alignment of the highfrequency antenna with the communications device comprises: sending,using the low frequency channel, second scanning information to thecommunications device, or receiving the second scanning information fromthe communications device, wherein the second scanning informationindicates a scanning sub-sector division manner, a quantity of scanningsub-sectors of a scanning sector corresponding to the first serialnumber and the scanning sub-sector division manner, or a quantity ofscanning sub-sectors of a scanning sector corresponding to the secondserial number, wherein the quantity of scanning sub-sectors of thescanning sector corresponding to the first serial number is H, whereinthe quantity of scanning sub-sectors of the scanning sectorcorresponding to the second serial number is P, wherein H is a positiveinteger, and wherein P is a positive integer; sending, by the accessdevice, the high-frequency narrow beam to the communications device in ascanning sub-sector of the scanning sector corresponding to the firstserial number such that the communications device receives thehigh-frequency narrow beam in a scanning sub-sector of the scanningsector corresponding to the second serial number, wherein a thirdscanning sector is any one of the H scanning sub-sectors, and wherein afourth scanning sector is any one of the P scanning sub-sectors;receiving a third serial number of the third scanning sector and afourth serial number of the fourth scanning sector, wherein the thirdserial number and the fourth serial number correspond to a secondmaximum receiving statistic from the communications device, and whereinthe second maximum receiving statistic is a maximum value in H×Preceiving statistics of received signals on H×P high-frequency narrowbeams determined by the communications device; and performing the highfrequency beam alignment of the high frequency antenna with thecommunications device according to the third serial number and thefourth serial number.
 6. The method according to claim 1, wherein thefirst maximum receiving statistic comprises at least one of: a powerparameter; a signal-to-noise ratio (SNR) parameter; or a received signallevel parameter.
 7. The method according to claim 1, wherein beforeperforming the high frequency beam alignment of the high frequencyantenna with the communications device, the method further comprises:performing mutual authentication with the communications device usingthe low frequency channel; or sending high-frequency frequencyinformation to the communications device using the low frequencychannel.
 8. The method according to claim 7, wherein performing the highfrequency beam alignment of the high frequency antenna with thecommunications device comprises: sending, using the low frequencychannel, a scanning start time to the communications device, orreceiving the scanning start time from the communications device; andstarting, at the scanning start time to perform the high frequency beamalignment of the high frequency antenna with the communications deviceaccording to the scanning range of the high frequency beam.
 9. Anapparatus for aligning antenna beams in a high-low frequency co-sitenetwork, comprising: a memory comprising instructions; and a processorcoupled to the memory, wherein the instructions when executed cause theprocessor to be configured to: establish a low frequency channel with alow frequency antenna of a communications device; obtain locationinformation of the communications device using the established lowfrequency channel; determine a scanning range of a high frequency beamaccording to the location information of the communications device; andperform high frequency beam alignment of a high frequency antenna withthe communications device according to the scanning range of the highfrequency beam; wherein the apparatus is an access device of thecommunications device, and wherein the instructions further cause theprocessor to be configured to: send, using the low frequency channel,first scanning information to the communications device, or receive thefirst scanning information from the communications device, wherein thefirst scanning information indicates a scanning sector division manner,a quantity of scanning sectors of the communications device and thescanning sector division manner, or a quantity of scanning sectors ofthe access device; and perform the high frequency beam alignment of thehigh frequency antenna according to the first scanning information;wherein the instructions further cause the processor to be configuredto: send, a high-frequency narrow beam to the communications device in afirst scanning sector such that the communications device receives thehigh-frequency narrow beam in a second scanning sector, wherein thefirst scanning sector is any one of Q scanning sectors, and wherein thesecond scanning sector is any one of N scanning sectors; receive a firstserial number of the first scanning sector and a second serial number ofthe second scanning sector, wherein the first serial number and thesecond serial number correspond to a first maximum receiving statisticfrom the communications device, and wherein the first maximum receivingstatistic is a maximum value in Q×N receiving statistics of receivedsignals on Q×N high-frequency narrow beams determined by thecommunications device; and perform the high frequency beam alignment ofthe high frequency antenna with the communications device according tothe first serial number and the second serial number, wherein thequantity of scanning sectors of the communications device is N, whereinthe quantity of scanning sectors of the access device is Q, wherein N isa positive integer, and wherein Q is a positive integer.
 10. Theapparatus according to claim 9, wherein the instructions when executedfurther cause the processor to be configured to receive, using the lowfrequency channel, the location information of the communications devicedetermined using a global positioning system (GPS) from thecommunications device.
 11. The apparatus according to claim 9, whereinthe instructions when executed further cause the processor to beconfigured to: estimate a direction of arrival (DOA) of a low frequencybeam using the low frequency channel in order to obtain DOA informationof the low frequency beam; and determine the location information of thecommunications device according to the DOA information of the lowfrequency beam.
 12. The apparatus according to claim 9, wherein theinstructions when executed further cause the processor to be configuredto: send M high-frequency narrow beams to the communications deviceaccording to the scanning range of the high frequency beam, wherein eachhigh-frequency narrow beam carries identity (ID) information indicatingan ID of each high-frequency narrow beam, and wherein M is a positiveinteger; receive a first ID of a first high-frequency narrow beamcorresponding to a second maximum receiving statistic from thecommunications device, wherein the second maximum receiving statistic isa maximum value in M receiving statistics of received signals on the Mhigh-frequency narrow beams received by the communications device, andwherein the first high-frequency narrow beam is one of the Mhigh-frequency narrow beams; send the first high-frequency narrow beamto the communications device; and perform the high frequency beamalignment of the high frequency antenna with the communications deviceaccording to the first ID.
 13. The apparatus according to claim 9,wherein the instructions when executed further cause the processor to beconfigured to: send, using the low frequency channel, second scanninginformation to the communications device, or receive the second scanninginformation from the communications device, wherein the second scanninginformation indicates a scanning sub-sector division manner, a quantityof scanning sub-sectors of a scanning sector corresponding to the firstserial number and the scanning sub-sector division manner, or a quantityof scanning sub-sectors of a scanning sector corresponding to the secondserial number, wherein the quantity of scanning sub-sectors of thescanning sector corresponding to the first serial number is H, whereinthe quantity of scanning sub-sectors of the scanning sectorcorresponding to the second serial number is P, wherein H is a positiveinteger, and wherein P is a positive integer; send, by the accessdevice, the high-frequency narrow beam to the communications device in ascanning sub-sector of the scanning sector corresponding to the firstserial number such that the communications device receives thehigh-frequency narrow beam in a scanning sub-sector of the scanningsector corresponding to the second serial number, wherein a thirdscanning sector is any one of the H scanning sub-sectors, and wherein afourth scanning sector is any one of the P scanning sub-sectors; receivea third serial number of the third scanning sector and a fourth serialnumber of the fourth scanning sector, wherein the third serial numberand the fourth serial number correspond to a second maximum receivingstatistic from the communications device, and wherein the second maximumreceiving statistic is a maximum value in H×P receiving statistics ofreceived signals on H×P high-frequency narrow beams determined by thecommunications device; and perform the high frequency beam alignment ofthe high frequency antenna with the communications device according tothe third serial number and the fourth serial number.
 14. The apparatusaccording to claim 9, wherein the first maximum receiving statisticcomprises at least one of: a power parameter; a signal-to-noise ratioparameter; or a received signal level parameter.
 15. The apparatusaccording to claim 9, wherein the instructions when executed furthercause the processor to be configured to: perform mutual authenticationwith the communications device using the low frequency channel; or sendhigh-frequency frequency information to the communications device usingthe low frequency channel.
 16. The apparatus according to claim 9,wherein the instructions when executed further cause the processor to beconfigured to: send, using the low frequency channel, a scanning starttime to the communications device, or receive the scanning start timefrom the communications device; and start, at the scanning start time toperform the high frequency beam alignment of the high frequency antennawith the communications device according to the scanning range of thehigh frequency beam.